diff --git a/contrib/perf.py b/contrib/perf.py
--- a/contrib/perf.py
+++ b/contrib/perf.py
@@ -3634,7 +3634,7 @@
     Result is the number of markers in the repo."""
     timer, fm = gettimer(ui)
     svfs = getsvfs(repo)
-    timer(lambda: len(obsolete.obsstore(svfs)))
+    timer(lambda: len(obsolete.obsstore(repo, svfs)))
     fm.end()
 
 
diff --git a/hgext/absorb.py b/hgext/absorb.py
--- a/hgext/absorb.py
+++ b/hgext/absorb.py
@@ -36,6 +36,10 @@
 import collections
 
 from mercurial.i18n import _
+from mercurial.node import (
+    hex,
+    short,
+)
 from mercurial import (
     cmdutil,
     commands,
@@ -44,7 +48,6 @@
     error,
     linelog,
     mdiff,
-    node,
     obsolete,
     patch,
     phases,
@@ -98,11 +101,14 @@
 class emptyfilecontext(object):
     """minimal filecontext representing an empty file"""
 
+    def __init__(self, repo):
+        self._repo = repo
+
     def data(self):
         return b''
 
     def node(self):
-        return node.nullid
+        return self._repo.nullid
 
 
 def uniq(lst):
@@ -208,7 +214,7 @@
         if path in pctx:
             fctxs.append(pctx[path])
         else:
-            fctxs.append(emptyfilecontext())
+            fctxs.append(emptyfilecontext(pctx.repo()))
 
     fctxs.reverse()
     # note: we rely on a property of hg: filerev is not reused for linear
@@ -367,7 +373,7 @@
                 idx = (max(rev - 1, 0)) // 2
                 self.ui.write(
                     _(b'%s: chunk %d:%d -> %d lines\n')
-                    % (node.short(self.fctxs[idx].node()), a1, a2, len(blines))
+                    % (short(self.fctxs[idx].node()), a1, a2, len(blines))
                 )
             self.linelog.replacelines(rev, a1, a2, b1, b2)
         if self.opts.get(b'edit_lines', False):
@@ -486,7 +492,7 @@
             editortext += _(b'HG: %s/%s %s %s\n') % (
                 b'|' * i,
                 b'-' * (len(visiblefctxs) - i + 1),
-                node.short(f.node()),
+                short(f.node()),
                 f.description().split(b'\n', 1)[0],
             )
         editortext += _(b'HG: %s\n') % (b'|' * len(visiblefctxs))
@@ -816,7 +822,7 @@
         if self.ui.debugflag:
             return b'%d:%s' % (ctx.rev(), ctx.hex())
         else:
-            return b'%d:%s' % (ctx.rev(), node.short(ctx.node()))
+            return b'%d:%s' % (ctx.rev(), short(ctx.node()))
 
     def _getnewfilecontents(self, ctx):
         """(ctx) -> {path: str}
@@ -849,7 +855,7 @@
                 changes.append((name, hsh))
                 if self.ui.verbose:
                     self.ui.write(
-                        _(b'moving bookmark %s to %s\n') % (name, node.hex(hsh))
+                        _(b'moving bookmark %s to %s\n') % (name, hex(hsh))
                     )
             else:
                 changes.append((name, None))
@@ -920,7 +926,7 @@
         the commit is a clone from ctx, with a (optionally) different p1, and
         different file contents replaced by memworkingcopy.
         """
-        parents = p1 and (p1, node.nullid)
+        parents = p1 and (p1, self.repo.nullid)
         extra = ctx.extra()
         if self._useobsolete and self.ui.configbool(b'absorb', b'add-noise'):
             extra[b'absorb_source'] = ctx.hex()
diff --git a/hgext/convert/git.py b/hgext/convert/git.py
--- a/hgext/convert/git.py
+++ b/hgext/convert/git.py
@@ -9,10 +9,10 @@
 import os
 
 from mercurial.i18n import _
+from mercurial.node import sha1nodeconstants
 from mercurial import (
     config,
     error,
-    node as nodemod,
     pycompat,
 )
 
@@ -192,7 +192,7 @@
         return heads
 
     def catfile(self, rev, ftype):
-        if rev == nodemod.nullhex:
+        if rev == sha1nodeconstants.nullhex:
             raise IOError
         self.catfilepipe[0].write(rev + b'\n')
         self.catfilepipe[0].flush()
@@ -214,7 +214,7 @@
         return data
 
     def getfile(self, name, rev):
-        if rev == nodemod.nullhex:
+        if rev == sha1nodeconstants.nullhex:
             return None, None
         if name == b'.hgsub':
             data = b'\n'.join([m.hgsub() for m in self.submoditer()])
@@ -228,7 +228,7 @@
         return data, mode
 
     def submoditer(self):
-        null = nodemod.nullhex
+        null = sha1nodeconstants.nullhex
         for m in sorted(self.submodules, key=lambda p: p.path):
             if m.node != null:
                 yield m
@@ -316,7 +316,7 @@
                 subexists[0] = True
                 if entry[4] == b'D' or renamesource:
                     subdeleted[0] = True
-                    changes.append((b'.hgsub', nodemod.nullhex))
+                    changes.append((b'.hgsub', sha1nodeconstants.nullhex))
                 else:
                     changes.append((b'.hgsub', b''))
             elif entry[1] == b'160000' or entry[0] == b':160000':
@@ -324,7 +324,7 @@
                     subexists[0] = True
             else:
                 if renamesource:
-                    h = nodemod.nullhex
+                    h = sha1nodeconstants.nullhex
                 self.modecache[(f, h)] = (p and b"x") or (s and b"l") or b""
                 changes.append((f, h))
 
@@ -361,7 +361,7 @@
 
         if subexists[0]:
             if subdeleted[0]:
-                changes.append((b'.hgsubstate', nodemod.nullhex))
+                changes.append((b'.hgsubstate', sha1nodeconstants.nullhex))
             else:
                 self.retrievegitmodules(version)
                 changes.append((b'.hgsubstate', b''))
diff --git a/hgext/convert/hg.py b/hgext/convert/hg.py
--- a/hgext/convert/hg.py
+++ b/hgext/convert/hg.py
@@ -24,6 +24,11 @@
 
 from mercurial.i18n import _
 from mercurial.pycompat import open
+from mercurial.node import (
+    bin,
+    hex,
+    sha1nodeconstants,
+)
 from mercurial import (
     bookmarks,
     context,
@@ -32,7 +37,6 @@
     hg,
     lock as lockmod,
     merge as mergemod,
-    node as nodemod,
     phases,
     pycompat,
     scmutil,
@@ -155,7 +159,7 @@
                 continue
             revid = revmap.get(source.lookuprev(s[0]))
             if not revid:
-                if s[0] == nodemod.nullhex:
+                if s[0] == sha1nodeconstants.nullhex:
                     revid = s[0]
                 else:
                     # missing, but keep for hash stability
@@ -174,7 +178,7 @@
 
             revid = s[0]
             subpath = s[1]
-            if revid != nodemod.nullhex:
+            if revid != sha1nodeconstants.nullhex:
                 revmap = self.subrevmaps.get(subpath)
                 if revmap is None:
                     revmap = mapfile(
@@ -295,13 +299,13 @@
         parents = pl
         nparents = len(parents)
         if self.filemapmode and nparents == 1:
-            m1node = self.repo.changelog.read(nodemod.bin(parents[0]))[0]
+            m1node = self.repo.changelog.read(bin(parents[0]))[0]
             parent = parents[0]
 
         if len(parents) < 2:
-            parents.append(nodemod.nullid)
+            parents.append(self.repo.nullid)
         if len(parents) < 2:
-            parents.append(nodemod.nullid)
+            parents.append(self.repo.nullid)
         p2 = parents.pop(0)
 
         text = commit.desc
@@ -332,12 +336,12 @@
 
             # Only transplant stores its reference in binary
             if label == b'transplant_source':
-                node = nodemod.hex(node)
+                node = hex(node)
 
             newrev = revmap.get(node)
             if newrev is not None:
                 if label == b'transplant_source':
-                    newrev = nodemod.bin(newrev)
+                    newrev = bin(newrev)
 
                 extra[label] = newrev
 
@@ -351,7 +355,7 @@
             p2 = parents.pop(0)
             p1ctx = self.repo[p1]
             p2ctx = None
-            if p2 != nodemod.nullid:
+            if p2 != self.repo.nullid:
                 p2ctx = self.repo[p2]
             fileset = set(files)
             if full:
@@ -389,7 +393,7 @@
                     origctx = commit.ctx
                 else:
                     origctx = None
-                node = nodemod.hex(self.repo.commitctx(ctx, origctx=origctx))
+                node = hex(self.repo.commitctx(ctx, origctx=origctx))
 
                 # If the node value has changed, but the phase is lower than
                 # draft, set it back to draft since it hasn't been exposed
@@ -406,7 +410,7 @@
 
         if self.filemapmode and nparents == 1:
             man = self.repo.manifestlog.getstorage(b'')
-            mnode = self.repo.changelog.read(nodemod.bin(p2))[0]
+            mnode = self.repo.changelog.read(bin(p2))[0]
             closed = b'close' in commit.extra
             if not closed and not man.cmp(m1node, man.revision(mnode)):
                 self.ui.status(_(b"filtering out empty revision\n"))
@@ -416,7 +420,7 @@
 
     def puttags(self, tags):
         tagparent = self.repo.branchtip(self.tagsbranch, ignoremissing=True)
-        tagparent = tagparent or nodemod.nullid
+        tagparent = tagparent or self.repo.nullid
 
         oldlines = set()
         for branch, heads in pycompat.iteritems(self.repo.branchmap()):
@@ -468,7 +472,7 @@
             extra,
         )
         node = self.repo.commitctx(ctx)
-        return nodemod.hex(node), nodemod.hex(tagparent)
+        return hex(node), hex(tagparent)
 
     def setfilemapmode(self, active):
         self.filemapmode = active
@@ -484,7 +488,7 @@
             self.ui.status(_(b"updating bookmarks\n"))
             destmarks = self.repo._bookmarks
             changes = [
-                (bookmark, nodemod.bin(updatedbookmark[bookmark]))
+                (bookmark, bin(updatedbookmark[bookmark]))
                 for bookmark in updatedbookmark
             ]
             destmarks.applychanges(self.repo, tr, changes)
@@ -577,7 +581,7 @@
         return [p for p in ctx.parents() if p and self.keep(p.node())]
 
     def getheads(self):
-        return [nodemod.hex(h) for h in self._heads if self.keep(h)]
+        return [hex(h) for h in self._heads if self.keep(h)]
 
     def getfile(self, name, rev):
         try:
@@ -678,9 +682,7 @@
             for t in self.repo.tagslist()
             if self.repo.tagtype(t[0]) == b'global'
         ]
-        return {
-            name: nodemod.hex(node) for name, node in tags if self.keep(node)
-        }
+        return {name: hex(node) for name, node in tags if self.keep(node)}
 
     def getchangedfiles(self, rev, i):
         ctx = self._changectx(rev)
@@ -718,7 +720,7 @@
 
     def lookuprev(self, rev):
         try:
-            return nodemod.hex(self.repo.lookup(rev))
+            return hex(self.repo.lookup(rev))
         except (error.RepoError, error.LookupError):
             return None
 
diff --git a/hgext/extdiff.py b/hgext/extdiff.py
--- a/hgext/extdiff.py
+++ b/hgext/extdiff.py
@@ -91,7 +91,7 @@
 
 from mercurial.i18n import _
 from mercurial.node import (
-    nullid,
+    nullrev,
     short,
 )
 from mercurial import (
@@ -551,7 +551,7 @@
         if not revs:
             ctx1b = repo[None].p2()
         else:
-            ctx1b = repo[nullid]
+            ctx1b = repo[nullrev]
 
     node1a = ctx1a.node()
     node1b = ctx1b.node()
@@ -559,7 +559,7 @@
 
     # Disable 3-way merge if there is only one parent
     if do3way:
-        if node1b == nullid:
+        if node1b == repo.nullid:
             do3way = False
 
     matcher = scmutil.match(repo[node2], pats, opts)
diff --git a/hgext/fastannotate/context.py b/hgext/fastannotate/context.py
--- a/hgext/fastannotate/context.py
+++ b/hgext/fastannotate/context.py
@@ -17,12 +17,16 @@
     open,
     setattr,
 )
+from mercurial.node import (
+    bin,
+    hex,
+    short,
+)
 from mercurial import (
     error,
     linelog as linelogmod,
     lock as lockmod,
     mdiff,
-    node,
     pycompat,
     scmutil,
     util,
@@ -150,7 +154,7 @@
     diffoptstr = stringutil.pprint(
         sorted((k, getattr(diffopts, k)) for k in mdiff.diffopts.defaults)
     )
-    return node.hex(hashutil.sha1(diffoptstr).digest())[:6]
+    return hex(hashutil.sha1(diffoptstr).digest())[:6]
 
 
 _defaultdiffopthash = hashdiffopts(mdiff.defaultopts)
@@ -308,7 +312,7 @@
         # command could give us a revision number even if the user passes a
         # commit hash.
         if isinstance(rev, int):
-            rev = node.hex(self.repo.changelog.node(rev))
+            rev = hex(self.repo.changelog.node(rev))
 
         # fast path: if rev is in the main branch already
         directly, revfctx = self.canannotatedirectly(rev)
@@ -493,7 +497,7 @@
         result = True
         f = None
         if not isinstance(rev, int) and rev is not None:
-            hsh = {20: bytes, 40: node.bin}.get(len(rev), lambda x: None)(rev)
+            hsh = {20: bytes, 40: bin}.get(len(rev), lambda x: None)(rev)
             if hsh is not None and (hsh, self.path) in self.revmap:
                 f = hsh
         if f is None:
@@ -598,7 +602,7 @@
                             self.ui.debug(
                                 b'fastannotate: reading %s line #%d '
                                 b'to resolve lines %r\n'
-                                % (node.short(hsh), linenum, idxs)
+                                % (short(hsh), linenum, idxs)
                             )
                         fctx = self._resolvefctx(hsh, revmap.rev2path(rev))
                         lines = mdiff.splitnewlines(fctx.data())
@@ -610,8 +614,7 @@
 
             # run the annotate and the lines should match to the file content
             self.ui.debug(
-                b'fastannotate: annotate %s to resolve lines\n'
-                % node.short(hsh)
+                b'fastannotate: annotate %s to resolve lines\n' % short(hsh)
             )
             linelog.annotate(rev)
             fctx = self._resolvefctx(hsh, revmap.rev2path(rev))
@@ -640,12 +643,10 @@
             hsh = f.node()
         llrev = self.revmap.hsh2rev(hsh)
         if not llrev:
-            raise faerror.CorruptedFileError(
-                b'%s is not in revmap' % node.hex(hsh)
-            )
+            raise faerror.CorruptedFileError(b'%s is not in revmap' % hex(hsh))
         if (self.revmap.rev2flag(llrev) & revmapmod.sidebranchflag) != 0:
             raise faerror.CorruptedFileError(
-                b'%s is not in revmap mainbranch' % node.hex(hsh)
+                b'%s is not in revmap mainbranch' % hex(hsh)
             )
         self.linelog.annotate(llrev)
         result = [
diff --git a/hgext/fastannotate/formatter.py b/hgext/fastannotate/formatter.py
--- a/hgext/fastannotate/formatter.py
+++ b/hgext/fastannotate/formatter.py
@@ -6,9 +6,12 @@
 # GNU General Public License version 2 or any later version.
 from __future__ import absolute_import
 
+from mercurial.node import (
+    hex,
+    short,
+)
 from mercurial import (
     encoding,
-    node,
     pycompat,
     templatefilters,
     util,
@@ -116,9 +119,9 @@
     @util.propertycache
     def _hexfunc(self):
         if self.ui.debugflag or self.opts.get(b'long_hash'):
-            return node.hex
+            return hex
         else:
-            return node.short
+            return short
 
     def end(self):
         pass
@@ -168,7 +171,7 @@
 
     @util.propertycache
     def _hexfunc(self):
-        return node.hex
+        return hex
 
     def end(self):
         self.ui.write(b'\n]\n')
diff --git a/hgext/fix.py b/hgext/fix.py
--- a/hgext/fix.py
+++ b/hgext/fix.py
@@ -131,8 +131,10 @@
 import subprocess
 
 from mercurial.i18n import _
-from mercurial.node import nullrev
-from mercurial.node import wdirrev
+from mercurial.node import (
+    nullrev,
+    wdirrev,
+)
 
 from mercurial.utils import procutil
 
diff --git a/hgext/git/dirstate.py b/hgext/git/dirstate.py
--- a/hgext/git/dirstate.py
+++ b/hgext/git/dirstate.py
@@ -4,11 +4,11 @@
 import errno
 import os
 
+from mercurial.node import sha1nodeconstants
 from mercurial import (
     error,
     extensions,
     match as matchmod,
-    node as nodemod,
     pycompat,
     scmutil,
     util,
@@ -81,14 +81,16 @@
         except pygit2.GitError:
             # Typically happens when peeling HEAD fails, as in an
             # empty repository.
-            return nodemod.nullid
+            return sha1nodeconstants.nullid
 
     def p2(self):
         # TODO: MERGE_HEAD? something like that, right?
-        return nodemod.nullid
+        return sha1nodeconstants.nullid
 
-    def setparents(self, p1, p2=nodemod.nullid):
-        assert p2 == nodemod.nullid, b'TODO merging support'
+    def setparents(self, p1, p2=None):
+        if p2 is None:
+            p2 = sha1nodeconstants.nullid
+        assert p2 == sha1nodeconstants.nullid, b'TODO merging support'
         self.git.head.set_target(gitutil.togitnode(p1))
 
     @util.propertycache
@@ -102,7 +104,7 @@
 
     def parents(self):
         # TODO how on earth do we find p2 if a merge is in flight?
-        return self.p1(), nodemod.nullid
+        return self.p1(), sha1nodeconstants.nullid
 
     def __iter__(self):
         return (pycompat.fsencode(f.path) for f in self.git.index)
diff --git a/hgext/git/gitlog.py b/hgext/git/gitlog.py
--- a/hgext/git/gitlog.py
+++ b/hgext/git/gitlog.py
@@ -1,6 +1,12 @@
 from __future__ import absolute_import
 
 from mercurial.i18n import _
+from mercurial.node import (
+    bin,
+    hex,
+    nullrev,
+    sha1nodeconstants,
+)
 
 from mercurial import (
     ancestor,
@@ -9,7 +15,6 @@
     encoding,
     error,
     manifest,
-    node as nodemod,
     pycompat,
 )
 from mercurial.interfaces import (
@@ -39,7 +44,7 @@
         )
 
     def rev(self, n):
-        if n == nodemod.nullid:
+        if n == sha1nodeconstants.nullid:
             return -1
         t = self._db.execute(
             'SELECT rev FROM changelog WHERE node = ?', (gitutil.togitnode(n),)
@@ -49,14 +54,14 @@
         return t[0]
 
     def node(self, r):
-        if r == nodemod.nullrev:
-            return nodemod.nullid
+        if r == nullrev:
+            return sha1nodeconstants.nullid
         t = self._db.execute(
             'SELECT node FROM changelog WHERE rev = ?', (r,)
         ).fetchone()
         if t is None:
             raise error.LookupError(r, b'00changelog.i', _(b'no node'))
-        return nodemod.bin(t[0])
+        return bin(t[0])
 
     def hasnode(self, n):
         t = self._db.execute(
@@ -123,10 +128,10 @@
     @property
     def nodemap(self):
         r = {
-            nodemod.bin(v[0]): v[1]
+            bin(v[0]): v[1]
             for v in self._db.execute('SELECT node, rev FROM changelog')
         }
-        r[nodemod.nullid] = nodemod.nullrev
+        r[sha1nodeconstants.nullid] = nullrev
         return r
 
     def tip(self):
@@ -134,8 +139,8 @@
             'SELECT node FROM changelog ORDER BY rev DESC LIMIT 1'
         ).fetchone()
         if t:
-            return nodemod.bin(t[0])
-        return nodemod.nullid
+            return bin(t[0])
+        return sha1nodeconstants.nullid
 
     def revs(self, start=0, stop=None):
         if stop is None:
@@ -150,23 +155,21 @@
 
     def tiprev(self):
         t = self._db.execute(
-            'SELECT rev FROM changelog '
-            'ORDER BY REV DESC '
-            'LIMIT 1'
+            'SELECT rev FROM changelog ' 'ORDER BY REV DESC ' 'LIMIT 1'
         )
         return next(t)
 
     def _partialmatch(self, id):
-        if nodemod.wdirhex.startswith(id):
+        if sha1nodeconstants.wdirhex.startswith(id):
             raise error.WdirUnsupported
         candidates = [
-            nodemod.bin(x[0])
+            bin(x[0])
             for x in self._db.execute(
                 'SELECT node FROM changelog WHERE node LIKE ?', (id + b'%',)
             )
         ]
-        if nodemod.nullhex.startswith(id):
-            candidates.append(nodemod.nullid)
+        if sha1nodeconstants.nullhex.startswith(id):
+            candidates.append(sha1nodeconstants.nullid)
         if len(candidates) > 1:
             raise error.AmbiguousPrefixLookupError(
                 id, b'00changelog.i', _(b'ambiguous identifier')
@@ -179,7 +182,7 @@
         return 0
 
     def shortest(self, node, minlength=1):
-        nodehex = nodemod.hex(node)
+        nodehex = hex(node)
         for attempt in pycompat.xrange(minlength, len(nodehex) + 1):
             candidate = nodehex[:attempt]
             matches = int(
@@ -211,7 +214,7 @@
         else:
             n = nodeorrev
         # handle looking up nullid
-        if n == nodemod.nullid:
+        if n == sha1nodeconstants.nullid:
             return hgchangelog._changelogrevision(extra={})
         hn = gitutil.togitnode(n)
         # We've got a real commit!
@@ -228,7 +231,7 @@
             for r in self._db.execute(
                 'SELECT filename FROM changedfiles '
                 'WHERE node = ? and filenode = ?',
-                (hn, nodemod.nullhex),
+                (hn, sha1nodeconstants.nullhex),
             )
         ]
         c = self.gitrepo[hn]
@@ -269,7 +272,7 @@
         nullrev.
         """
         if common is None:
-            common = [nodemod.nullrev]
+            common = [nullrev]
 
         return ancestor.incrementalmissingancestors(self.parentrevs, common)
 
@@ -289,7 +292,7 @@
         not supplied, uses all of the revlog's heads.  If common is not
         supplied, uses nullid."""
         if common is None:
-            common = [nodemod.nullid]
+            common = [sha1nodeconstants.nullid]
         if heads is None:
             heads = self.heads()
 
@@ -304,12 +307,12 @@
         c = []
         p = self.rev(node)
         for r in self.revs(start=p + 1):
-            prevs = [pr for pr in self.parentrevs(r) if pr != nodemod.nullrev]
+            prevs = [pr for pr in self.parentrevs(r) if pr != nullrev]
             if prevs:
                 for pr in prevs:
                     if pr == p:
                         c.append(self.node(r))
-            elif p == nodemod.nullrev:
+            elif p == nullrev:
                 c.append(self.node(r))
         return c
 
@@ -325,7 +328,7 @@
 
     # Cleanup opportunity: this is *identical* to the revlog.py version
     def isancestorrev(self, a, b):
-        if a == nodemod.nullrev:
+        if a == nullrev:
             return True
         elif a == b:
             return True
@@ -339,8 +342,8 @@
         if hn != gitutil.nullgit:
             c = self.gitrepo[hn]
         else:
-            return nodemod.nullrev, nodemod.nullrev
-        p1 = p2 = nodemod.nullrev
+            return nullrev, nullrev
+        p1 = p2 = nullrev
         if c.parents:
             p1 = self.rev(c.parents[0].id.raw)
             if len(c.parents) > 2:
@@ -388,9 +391,9 @@
     ):
         parents = []
         hp1, hp2 = gitutil.togitnode(p1), gitutil.togitnode(p2)
-        if p1 != nodemod.nullid:
+        if p1 != sha1nodeconstants.nullid:
             parents.append(hp1)
-        if p2 and p2 != nodemod.nullid:
+        if p2 and p2 != sha1nodeconstants.nullid:
             parents.append(hp2)
         assert date is not None
         timestamp, tz = date
@@ -421,7 +424,7 @@
         return self.get(b'', node)
 
     def get(self, relpath, node):
-        if node == nodemod.nullid:
+        if node == sha1nodeconstants.nullid:
             # TODO: this should almost certainly be a memgittreemanifestctx
             return manifest.memtreemanifestctx(self, relpath)
         commit = self.gitrepo[gitutil.togitnode(node)]
@@ -440,9 +443,10 @@
         super(filelog, self).__init__(gr, db)
         assert isinstance(path, bytes)
         self.path = path
+        self.nullid = sha1nodeconstants.nullid
 
     def read(self, node):
-        if node == nodemod.nullid:
+        if node == sha1nodeconstants.nullid:
             return b''
         return self.gitrepo[gitutil.togitnode(node)].data
 
@@ -452,7 +456,7 @@
         if isinstance(node, int):
             assert False, b'todo revnums for nodes'
         if len(node) == 40:
-            node = nodemod.bin(node)
+            node = bin(node)
         hnode = gitutil.togitnode(node)
         if hnode in self.gitrepo:
             return node
@@ -502,7 +506,7 @@
         ).fetchone()
         if maybe is None:
             raise IndexError('gitlog %r out of range %d' % (self.path, rev))
-        return nodemod.bin(maybe[0])
+        return bin(maybe[0])
 
     def parents(self, node):
         gn = gitutil.togitnode(node)
@@ -527,7 +531,7 @@
                 index.fill_in_filelog(self.gitrepo, self._db, commit, gp, gn)
                 return self.parents(node)
             else:
-                ps.append(nodemod.bin(p))
+                ps.append(bin(p))
         return ps
 
     def renamed(self, node):
diff --git a/hgext/git/gitutil.py b/hgext/git/gitutil.py
--- a/hgext/git/gitutil.py
+++ b/hgext/git/gitutil.py
@@ -1,7 +1,7 @@
 """utilities to assist in working with pygit2"""
 from __future__ import absolute_import
 
-from mercurial.node import bin, hex, nullid
+from mercurial.node import bin, hex, sha1nodeconstants
 
 from mercurial import pycompat
 
@@ -37,4 +37,4 @@
     return bin(n)
 
 
-nullgit = togitnode(nullid)
+nullgit = togitnode(sha1nodeconstants.nullid)
diff --git a/hgext/git/index.py b/hgext/git/index.py
--- a/hgext/git/index.py
+++ b/hgext/git/index.py
@@ -5,11 +5,11 @@
 import sqlite3
 
 from mercurial.i18n import _
+from mercurial.node import sha1nodeconstants
 
 from mercurial import (
     encoding,
     error,
-    node as nodemod,
     pycompat,
 )
 
@@ -278,7 +278,7 @@
     for pos, commit in enumerate(walker):
         if prog is not None:
             prog.update(pos)
-        p1 = p2 = nodemod.nullhex
+        p1 = p2 = sha1nodeconstants.nullhex
         if len(commit.parents) > 2:
             raise error.ProgrammingError(
                 (
@@ -317,7 +317,7 @@
             files = {
                 nf.path: nf.id.hex
                 for nf in new_files
-                if nf.id.raw != nodemod.nullid
+                if nf.id.raw != sha1nodeconstants.nullid
             }
             for p, n in files.items():
                 # We intentionally set NULLs for any file parentage
diff --git a/hgext/gpg.py b/hgext/gpg.py
--- a/hgext/gpg.py
+++ b/hgext/gpg.py
@@ -11,12 +11,16 @@
 import os
 
 from mercurial.i18n import _
+from mercurial.node import (
+    bin,
+    hex,
+    short,
+)
 from mercurial import (
     cmdutil,
     error,
     help,
     match,
-    node as hgnode,
     pycompat,
     registrar,
 )
@@ -144,7 +148,7 @@
     # read the heads
     fl = repo.file(b".hgsigs")
     for r in reversed(fl.heads()):
-        fn = b".hgsigs|%s" % hgnode.short(r)
+        fn = b".hgsigs|%s" % short(r)
         for item in parsefile(fl.read(r).splitlines(), fn):
             yield item
     try:
@@ -161,7 +165,7 @@
     fn, ln = context
     node, version, sig = sigdata
     prefix = b"%s:%d" % (fn, ln)
-    node = hgnode.bin(node)
+    node = bin(node)
 
     data = node2txt(repo, node, version)
     sig = binascii.a2b_base64(sig)
@@ -212,7 +216,7 @@
         revs[r].extend(keys)
     for rev in sorted(revs, reverse=True):
         for k in revs[rev]:
-            r = b"%5d:%s" % (rev, hgnode.hex(repo.changelog.node(rev)))
+            r = b"%5d:%s" % (rev, hex(repo.changelog.node(rev)))
             ui.write(b"%-30s %s\n" % (keystr(ui, k), r))
 
 
@@ -221,7 +225,7 @@
     """verify all the signatures there may be for a particular revision"""
     mygpg = newgpg(ui)
     rev = repo.lookup(rev)
-    hexrev = hgnode.hex(rev)
+    hexrev = hex(rev)
     keys = []
 
     for data, context in sigwalk(repo):
@@ -232,11 +236,11 @@
                 keys.extend(k)
 
     if not keys:
-        ui.write(_(b"no valid signature for %s\n") % hgnode.short(rev))
+        ui.write(_(b"no valid signature for %s\n") % short(rev))
         return
 
     # print summary
-    ui.write(_(b"%s is signed by:\n") % hgnode.short(rev))
+    ui.write(_(b"%s is signed by:\n") % short(rev))
     for key in keys:
         ui.write(b" %s\n" % keystr(ui, key))
 
@@ -299,7 +303,7 @@
         nodes = [repo.lookup(n) for n in revs]
     else:
         nodes = [
-            node for node in repo.dirstate.parents() if node != hgnode.nullid
+            node for node in repo.dirstate.parents() if node != repo.nullid
         ]
         if len(nodes) > 1:
             raise error.Abort(
@@ -309,10 +313,8 @@
             nodes = [repo.changelog.tip()]
 
     for n in nodes:
-        hexnode = hgnode.hex(n)
-        ui.write(
-            _(b"signing %d:%s\n") % (repo.changelog.rev(n), hgnode.short(n))
-        )
+        hexnode = hex(n)
+        ui.write(_(b"signing %d:%s\n") % (repo.changelog.rev(n), short(n)))
         # build data
         data = node2txt(repo, n, sigver)
         sig = mygpg.sign(data)
@@ -349,10 +351,7 @@
     if not message:
         # we don't translate commit messages
         message = b"\n".join(
-            [
-                b"Added signature for changeset %s" % hgnode.short(n)
-                for n in nodes
-            ]
+            [b"Added signature for changeset %s" % short(n) for n in nodes]
         )
     try:
         editor = cmdutil.getcommiteditor(
@@ -368,7 +367,7 @@
 def node2txt(repo, node, ver):
     """map a manifest into some text"""
     if ver == b"0":
-        return b"%s\n" % hgnode.hex(node)
+        return b"%s\n" % hex(node)
     else:
         raise error.Abort(_(b"unknown signature version"))
 
diff --git a/hgext/hgk.py b/hgext/hgk.py
--- a/hgext/hgk.py
+++ b/hgext/hgk.py
@@ -40,7 +40,6 @@
 
 from mercurial.i18n import _
 from mercurial.node import (
-    nullid,
     nullrev,
     short,
 )
@@ -93,7 +92,7 @@
         mmap2 = repo[node2].manifest()
         m = scmutil.match(repo[node1], files)
         st = repo.status(node1, node2, m)
-        empty = short(nullid)
+        empty = short(repo.nullid)
 
         for f in st.modified:
             # TODO get file permissions
@@ -315,9 +314,9 @@
             parentstr = b""
             if parents:
                 pp = repo.changelog.parents(n)
-                if pp[0] != nullid:
+                if pp[0] != repo.nullid:
                     parentstr += b" " + short(pp[0])
-                if pp[1] != nullid:
+                if pp[1] != repo.nullid:
                     parentstr += b" " + short(pp[1])
             if not full:
                 ui.write(b"%s%s\n" % (short(n), parentstr))
diff --git a/hgext/histedit.py b/hgext/histedit.py
--- a/hgext/histedit.py
+++ b/hgext/histedit.py
@@ -209,6 +209,11 @@
     getattr,
     open,
 )
+from mercurial.node import (
+    bin,
+    hex,
+    short,
+)
 from mercurial import (
     bundle2,
     cmdutil,
@@ -225,7 +230,6 @@
     merge as mergemod,
     mergestate as mergestatemod,
     mergeutil,
-    node,
     obsolete,
     pycompat,
     registrar,
@@ -392,8 +396,8 @@
 
     def _write(self, fp):
         fp.write(b'v1\n')
-        fp.write(b'%s\n' % node.hex(self.parentctxnode))
-        fp.write(b'%s\n' % node.hex(self.topmost))
+        fp.write(b'%s\n' % hex(self.parentctxnode))
+        fp.write(b'%s\n' % hex(self.topmost))
         fp.write(b'%s\n' % (b'True' if self.keep else b'False'))
         fp.write(b'%d\n' % len(self.actions))
         for action in self.actions:
@@ -403,8 +407,8 @@
             fp.write(
                 b'%s%s\n'
                 % (
-                    node.hex(replacement[0]),
-                    b''.join(node.hex(r) for r in replacement[1]),
+                    hex(replacement[0]),
+                    b''.join(hex(r) for r in replacement[1]),
                 )
             )
         backupfile = self.backupfile
@@ -420,10 +424,10 @@
         lines[index]  # version number
         index += 1
 
-        parentctxnode = node.bin(lines[index])
+        parentctxnode = bin(lines[index])
         index += 1
 
-        topmost = node.bin(lines[index])
+        topmost = bin(lines[index])
         index += 1
 
         keep = lines[index] == b'True'
@@ -446,9 +450,9 @@
         index += 1
         for i in pycompat.xrange(replacementlen):
             replacement = lines[index]
-            original = node.bin(replacement[:40])
+            original = bin(replacement[:40])
             succ = [
-                node.bin(replacement[i : i + 40])
+                bin(replacement[i : i + 40])
                 for i in range(40, len(replacement), 40)
             ]
             replacements.append((original, succ))
@@ -483,12 +487,12 @@
         # ruleid can be anything from rev numbers, hashes, "bookmarks" etc
         # Check for validation of rule ids and get the rulehash
         try:
-            rev = node.bin(ruleid)
+            rev = bin(ruleid)
         except TypeError:
             try:
                 _ctx = scmutil.revsingle(state.repo, ruleid)
                 rulehash = _ctx.hex()
-                rev = node.bin(rulehash)
+                rev = bin(rulehash)
             except error.RepoLookupError:
                 raise error.ParseError(_(b"invalid changeset %s") % ruleid)
         return cls(state, rev)
@@ -496,7 +500,7 @@
     def verify(self, prev, expected, seen):
         """ Verifies semantic correctness of the rule"""
         repo = self.repo
-        ha = node.hex(self.node)
+        ha = hex(self.node)
         self.node = scmutil.resolvehexnodeidprefix(repo, ha)
         if self.node is None:
             raise error.ParseError(_(b'unknown changeset %s listed') % ha[:12])
@@ -507,14 +511,13 @@
         if self.node not in expected:
             raise error.ParseError(
                 _(b'%s "%s" changeset was not a candidate')
-                % (self.verb, node.short(self.node)),
+                % (self.verb, short(self.node)),
                 hint=_(b'only use listed changesets'),
             )
         # and only one command per node
         if self.node in seen:
             raise error.ParseError(
-                _(b'duplicated command for changeset %s')
-                % node.short(self.node)
+                _(b'duplicated command for changeset %s') % short(self.node)
             )
 
     def torule(self):
@@ -546,7 +549,7 @@
         """Print an action in format used by histedit state files
            (the first line is a verb, the remainder is the second)
         """
-        return b"%s\n%s" % (self.verb, node.hex(self.node))
+        return b"%s\n%s" % (self.verb, hex(self.node))
 
     def run(self):
         """Runs the action. The default behavior is simply apply the action's
@@ -567,8 +570,7 @@
         repo.dirstate.setbranch(rulectx.branch())
         if stats.unresolvedcount:
             raise error.InterventionRequired(
-                _(b'Fix up the change (%s %s)')
-                % (self.verb, node.short(self.node)),
+                _(b'Fix up the change (%s %s)') % (self.verb, short(self.node)),
                 hint=_(b'hg histedit --continue to resume'),
             )
 
@@ -603,8 +605,7 @@
         ctx = self.repo[b'.']
         if ctx.node() == self.state.parentctxnode:
             self.repo.ui.warn(
-                _(b'%s: skipping changeset (no changes)\n')
-                % node.short(self.node)
+                _(b'%s: skipping changeset (no changes)\n') % short(self.node)
             )
             return ctx, [(self.node, tuple())]
         if ctx.node() == self.node:
@@ -673,7 +674,7 @@
     for c in ctxs:
         if not c.mutable():
             raise error.ParseError(
-                _(b"cannot fold into public change %s") % node.short(c.node())
+                _(b"cannot fold into public change %s") % short(c.node())
             )
     base = firstctx.p1()
 
@@ -775,7 +776,7 @@
     def run(self):
         rulectx = self.repo[self.node]
         if rulectx.p1().node() == self.state.parentctxnode:
-            self.repo.ui.debug(b'node %s unchanged\n' % node.short(self.node))
+            self.repo.ui.debug(b'node %s unchanged\n' % short(self.node))
             return rulectx, []
 
         return super(pick, self).run()
@@ -790,7 +791,7 @@
         applychanges(repo.ui, repo, rulectx, {})
         raise error.InterventionRequired(
             _(b'Editing (%s), you may commit or record as needed now.')
-            % node.short(self.node),
+            % short(self.node),
             hint=_(b'hg histedit --continue to resume'),
         )
 
@@ -812,7 +813,7 @@
             c = repo[prev.node]
         if not c.mutable():
             raise error.ParseError(
-                _(b"cannot fold into public change %s") % node.short(c.node())
+                _(b"cannot fold into public change %s") % short(c.node())
             )
 
     def continuedirty(self):
@@ -821,7 +822,7 @@
 
         commit = commitfuncfor(repo, rulectx)
         commit(
-            text=b'fold-temp-revision %s' % node.short(self.node),
+            text=b'fold-temp-revision %s' % short(self.node),
             user=rulectx.user(),
             date=rulectx.date(),
             extra=rulectx.extra(),
@@ -833,7 +834,7 @@
         rulectx = repo[self.node]
         parentctxnode = self.state.parentctxnode
         if ctx.node() == parentctxnode:
-            repo.ui.warn(_(b'%s: empty changeset\n') % node.short(self.node))
+            repo.ui.warn(_(b'%s: empty changeset\n') % short(self.node))
             return ctx, [(self.node, (parentctxnode,))]
 
         parentctx = repo[parentctxnode]
@@ -847,7 +848,7 @@
                     b'%s: cannot fold - working copy is not a '
                     b'descendant of previous commit %s\n'
                 )
-                % (node.short(self.node), node.short(parentctxnode))
+                % (short(self.node), short(parentctxnode))
             )
             return ctx, [(self.node, (ctx.node(),))]
 
@@ -961,7 +962,7 @@
         if self.node in expected:
             msg = _(b'%s "%s" changeset was an edited list candidate')
             raise error.ParseError(
-                msg % (self.verb, node.short(self.node)),
+                msg % (self.verb, short(self.node)),
                 hint=_(b'base must only use unlisted changesets'),
             )
 
@@ -1701,8 +1702,7 @@
         revs = between(repo, root, topmost, keep)
         if not revs:
             raise error.Abort(
-                _(b'%s is not an ancestor of working directory')
-                % node.short(root)
+                _(b'%s is not an ancestor of working directory') % short(root)
             )
 
         ctxs = []
@@ -2055,16 +2055,16 @@
     if mapping:
         for prec, succs in pycompat.iteritems(mapping):
             if not succs:
-                ui.debug(b'histedit: %s is dropped\n' % node.short(prec))
+                ui.debug(b'histedit: %s is dropped\n' % short(prec))
             else:
                 ui.debug(
                     b'histedit: %s is replaced by %s\n'
-                    % (node.short(prec), node.short(succs[0]))
+                    % (short(prec), short(succs[0]))
                 )
                 if len(succs) > 1:
                     m = b'histedit:                            %s'
                     for n in succs[1:]:
-                        ui.debug(m % node.short(n))
+                        ui.debug(m % short(n))
 
     if not state.keep:
         if mapping:
@@ -2109,7 +2109,7 @@
     try:
         state.read()
         __, leafs, tmpnodes, __ = processreplacement(state)
-        ui.debug(b'restore wc to old parent %s\n' % node.short(state.topmost))
+        ui.debug(b'restore wc to old parent %s\n' % short(state.topmost))
 
         # Recover our old commits if necessary
         if not state.topmost in repo and state.backupfile:
@@ -2163,7 +2163,7 @@
     state.read()
     if not rules:
         comment = geteditcomment(
-            ui, node.short(state.parentctxnode), node.short(state.topmost)
+            ui, short(state.parentctxnode), short(state.topmost)
         )
         rules = ruleeditor(repo, ui, state.actions, comment)
     else:
@@ -2204,7 +2204,7 @@
     revs = between(repo, root, topmost, state.keep)
     if not revs:
         raise error.Abort(
-            _(b'%s is not an ancestor of working directory') % node.short(root)
+            _(b'%s is not an ancestor of working directory') % short(root)
         )
 
     ctxs = [repo[r] for r in revs]
@@ -2241,7 +2241,7 @@
             )
 
     if not rules:
-        comment = geteditcomment(ui, node.short(root), node.short(topmost))
+        comment = geteditcomment(ui, short(root), short(topmost))
         actions = [pick(state, r) for r in revs]
         rules = ruleeditor(repo, ui, actions, comment)
     else:
@@ -2445,12 +2445,12 @@
         actions[:0] = drops
     elif missing:
         raise error.ParseError(
-            _(b'missing rules for changeset %s') % node.short(missing[0]),
+            _(b'missing rules for changeset %s') % short(missing[0]),
             hint=_(
                 b'use "drop %s" to discard, see also: '
                 b"'hg help -e histedit.config'"
             )
-            % node.short(missing[0]),
+            % short(missing[0]),
         )
 
 
@@ -2604,7 +2604,7 @@
         if common_nodes:
             raise error.Abort(
                 _(b"histedit in progress, can't strip %s")
-                % b', '.join(node.short(x) for x in common_nodes)
+                % b', '.join(short(x) for x in common_nodes)
             )
     return orig(ui, repo, nodelist, *args, **kwargs)
 
diff --git a/hgext/infinitepush/bundleparts.py b/hgext/infinitepush/bundleparts.py
--- a/hgext/infinitepush/bundleparts.py
+++ b/hgext/infinitepush/bundleparts.py
@@ -6,13 +6,13 @@
 from __future__ import absolute_import
 
 from mercurial.i18n import _
+from mercurial.node import hex
 
 from mercurial import (
     bundle2,
     changegroup,
     error,
     extensions,
-    node as nodemod,
     pycompat,
     revsetlang,
     util,
@@ -54,7 +54,7 @@
         params[b'bookprevnode'] = b''
         bookmarks = repo._bookmarks
         if bookmark in bookmarks:
-            params[b'bookprevnode'] = nodemod.hex(bookmarks[bookmark])
+            params[b'bookprevnode'] = hex(bookmarks[bookmark])
 
     # Do not send pushback bundle2 part with bookmarks if remotenames extension
     # is enabled. It will be handled manually in `_push()`
diff --git a/hgext/infinitepush/store.py b/hgext/infinitepush/store.py
--- a/hgext/infinitepush/store.py
+++ b/hgext/infinitepush/store.py
@@ -10,10 +10,9 @@
 import subprocess
 
 from mercurial.pycompat import open
-from mercurial import (
-    node,
-    pycompat,
-)
+from mercurial.node import hex
+from mercurial import pycompat
+
 from mercurial.utils import (
     hashutil,
     procutil,
@@ -86,7 +85,7 @@
         return os.path.join(self._dirpath(filename), filename)
 
     def write(self, data):
-        filename = node.hex(hashutil.sha1(data).digest())
+        filename = hex(hashutil.sha1(data).digest())
         dirpath = self._dirpath(filename)
 
         if not os.path.exists(dirpath):
diff --git a/hgext/journal.py b/hgext/journal.py
--- a/hgext/journal.py
+++ b/hgext/journal.py
@@ -19,6 +19,10 @@
 import weakref
 
 from mercurial.i18n import _
+from mercurial.node import (
+    bin,
+    hex,
+)
 
 from mercurial import (
     bookmarks,
@@ -31,7 +35,6 @@
     localrepo,
     lock,
     logcmdutil,
-    node,
     pycompat,
     registrar,
     util,
@@ -113,8 +116,8 @@
     new = list(new)
     if util.safehasattr(dirstate, 'journalstorage'):
         # only record two hashes if there was a merge
-        oldhashes = old[:1] if old[1] == node.nullid else old
-        newhashes = new[:1] if new[1] == node.nullid else new
+        oldhashes = old[:1] if old[1] == dirstate._nodeconstants.nullid else old
+        newhashes = new[:1] if new[1] == dirstate._nodeconstants.nullid else new
         dirstate.journalstorage.record(
             wdirparenttype, b'.', oldhashes, newhashes
         )
@@ -127,7 +130,7 @@
     if util.safehasattr(repo, 'journal'):
         oldmarks = bookmarks.bmstore(repo)
         for mark, value in pycompat.iteritems(store):
-            oldvalue = oldmarks.get(mark, node.nullid)
+            oldvalue = oldmarks.get(mark, repo.nullid)
             if value != oldvalue:
                 repo.journal.record(bookmarktype, mark, oldvalue, value)
     return orig(store, fp)
@@ -248,8 +251,8 @@
         ) = line.split(b'\n')
         timestamp, tz = time.split()
         timestamp, tz = float(timestamp), int(tz)
-        oldhashes = tuple(node.bin(hash) for hash in oldhashes.split(b','))
-        newhashes = tuple(node.bin(hash) for hash in newhashes.split(b','))
+        oldhashes = tuple(bin(hash) for hash in oldhashes.split(b','))
+        newhashes = tuple(bin(hash) for hash in newhashes.split(b','))
         return cls(
             (timestamp, tz),
             user,
@@ -263,8 +266,8 @@
     def __bytes__(self):
         """bytes representation for storage"""
         time = b' '.join(map(pycompat.bytestr, self.timestamp))
-        oldhashes = b','.join([node.hex(hash) for hash in self.oldhashes])
-        newhashes = b','.join([node.hex(hash) for hash in self.newhashes])
+        oldhashes = b','.join([hex(hash) for hash in self.oldhashes])
+        newhashes = b','.join([hex(hash) for hash in self.newhashes])
         return b'\n'.join(
             (
                 time,
diff --git a/hgext/largefiles/basestore.py b/hgext/largefiles/basestore.py
--- a/hgext/largefiles/basestore.py
+++ b/hgext/largefiles/basestore.py
@@ -10,8 +10,8 @@
 from __future__ import absolute_import
 
 from mercurial.i18n import _
-
-from mercurial import node, util
+from mercurial.node import short
+from mercurial import util
 
 from . import lfutil
 
@@ -134,7 +134,7 @@
         filestocheck = []  # list of (cset, filename, expectedhash)
         for rev in revs:
             cctx = self.repo[rev]
-            cset = b"%d:%s" % (cctx.rev(), node.short(cctx.node()))
+            cset = b"%d:%s" % (cctx.rev(), short(cctx.node()))
 
             for standin in cctx:
                 filename = lfutil.splitstandin(standin)
diff --git a/hgext/largefiles/lfcommands.py b/hgext/largefiles/lfcommands.py
--- a/hgext/largefiles/lfcommands.py
+++ b/hgext/largefiles/lfcommands.py
@@ -14,6 +14,10 @@
 import shutil
 
 from mercurial.i18n import _
+from mercurial.node import (
+    bin,
+    hex,
+)
 
 from mercurial import (
     cmdutil,
@@ -23,7 +27,6 @@
     hg,
     lock,
     match as matchmod,
-    node,
     pycompat,
     scmutil,
     util,
@@ -111,7 +114,7 @@
             rsrc[ctx]
             for ctx in rsrc.changelog.nodesbetween(None, rsrc.heads())[0]
         )
-        revmap = {node.nullid: node.nullid}
+        revmap = {rsrc.nullid: rdst.nullid}
         if tolfile:
             # Lock destination to prevent modification while it is converted to.
             # Don't need to lock src because we are just reading from its
@@ -275,7 +278,7 @@
                 # largefile was modified, update standins
                 m = hashutil.sha1(b'')
                 m.update(ctx[f].data())
-                hash = node.hex(m.digest())
+                hash = hex(m.digest())
                 if f not in lfiletohash or lfiletohash[f] != hash:
                     rdst.wwrite(f, ctx[f].data(), ctx[f].flags())
                     executable = b'x' in ctx[f].flags()
@@ -336,7 +339,7 @@
 # Generate list of changed files
 def _getchangedfiles(ctx, parents):
     files = set(ctx.files())
-    if node.nullid not in parents:
+    if ctx.repo().nullid not in parents:
         mc = ctx.manifest()
         for pctx in ctx.parents():
             for fn in pctx.manifest().diff(mc):
@@ -350,7 +353,7 @@
     for p in ctx.parents():
         parents.append(revmap[p.node()])
     while len(parents) < 2:
-        parents.append(node.nullid)
+        parents.append(ctx.repo().nullid)
     return parents
 
 
@@ -380,12 +383,12 @@
             ui.warn(_(b'skipping incorrectly formatted tag %s\n') % line)
             continue
         try:
-            newid = node.bin(id)
+            newid = bin(id)
         except TypeError:
             ui.warn(_(b'skipping incorrectly formatted id %s\n') % id)
             continue
         try:
-            newdata.append(b'%s %s\n' % (node.hex(revmap[newid]), name))
+            newdata.append(b'%s %s\n' % (hex(revmap[newid]), name))
         except KeyError:
             ui.warn(_(b'no mapping for id %s\n') % id)
             continue
diff --git a/hgext/largefiles/lfutil.py b/hgext/largefiles/lfutil.py
--- a/hgext/largefiles/lfutil.py
+++ b/hgext/largefiles/lfutil.py
@@ -24,7 +24,6 @@
     error,
     httpconnection,
     match as matchmod,
-    node,
     pycompat,
     scmutil,
     sparse,
@@ -204,6 +203,7 @@
         repo.root,
         repo.dirstate._validate,
         lambda: sparse.matcher(repo),
+        repo.nodeconstants,
     )
 
     # If the largefiles dirstate does not exist, populate and create
@@ -610,7 +610,7 @@
     ) as progress:
         for i, n in enumerate(missing):
             progress.update(i)
-            parents = [p for p in repo[n].parents() if p != node.nullid]
+            parents = [p for p in repo[n].parents() if p != repo.nullid]
 
             with lfstatus(repo, value=False):
                 ctx = repo[n]
diff --git a/hgext/lfs/__init__.py b/hgext/lfs/__init__.py
--- a/hgext/lfs/__init__.py
+++ b/hgext/lfs/__init__.py
@@ -125,6 +125,7 @@
 import sys
 
 from mercurial.i18n import _
+from mercurial.node import bin
 
 from mercurial import (
     bundlecaches,
@@ -137,7 +138,6 @@
     filesetlang,
     localrepo,
     minifileset,
-    node,
     pycompat,
     revlog,
     scmutil,
@@ -242,11 +242,10 @@
                 return 0
 
             last = kwargs.get('node_last')
-            _bin = node.bin
             if last:
-                s = repo.set(b'%n:%n', _bin(kwargs['node']), _bin(last))
+                s = repo.set(b'%n:%n', bin(kwargs['node']), bin(last))
             else:
-                s = repo.set(b'%n', _bin(kwargs['node']))
+                s = repo.set(b'%n', bin(kwargs['node']))
             match = repo._storenarrowmatch
             for ctx in s:
                 # TODO: is there a way to just walk the files in the commit?
diff --git a/hgext/lfs/blobstore.py b/hgext/lfs/blobstore.py
--- a/hgext/lfs/blobstore.py
+++ b/hgext/lfs/blobstore.py
@@ -17,12 +17,12 @@
 
 from mercurial.i18n import _
 from mercurial.pycompat import getattr
+from mercurial.node import hex
 
 from mercurial import (
     encoding,
     error,
     httpconnection as httpconnectionmod,
-    node,
     pathutil,
     pycompat,
     url as urlmod,
@@ -174,7 +174,7 @@
                 )
                 raise LfsRemoteError(_(msg) % (size, int(content_length)))
 
-            realoid = node.hex(sha256.digest())
+            realoid = hex(sha256.digest())
             if realoid != oid:
                 raise LfsCorruptionError(
                     _(b'corrupt remote lfs object: %s') % oid
@@ -225,7 +225,7 @@
             # Don't abort if corruption is detected, because `hg verify` will
             # give more useful info about the corruption- simply don't add the
             # hardlink.
-            if verify or node.hex(hashlib.sha256(blob).digest()) == oid:
+            if verify or hex(hashlib.sha256(blob).digest()) == oid:
                 self.ui.note(_(b'lfs: found %s in the usercache\n') % oid)
                 lfutil.link(self.cachevfs.join(oid), self.vfs.join(oid))
         else:
@@ -249,7 +249,7 @@
             for chunk in util.filechunkiter(fp, size=1048576):
                 sha256.update(chunk)
 
-        return oid == node.hex(sha256.digest())
+        return oid == hex(sha256.digest())
 
     def has(self, oid):
         """Returns True if the local blobstore contains the requested blob,
@@ -704,7 +704,7 @@
 
 
 def _verify(oid, content):
-    realoid = node.hex(hashlib.sha256(content).digest())
+    realoid = hex(hashlib.sha256(content).digest())
     if realoid != oid:
         raise LfsCorruptionError(
             _(b'detected corrupt lfs object: %s') % oid,
diff --git a/hgext/lfs/wrapper.py b/hgext/lfs/wrapper.py
--- a/hgext/lfs/wrapper.py
+++ b/hgext/lfs/wrapper.py
@@ -10,7 +10,7 @@
 import hashlib
 
 from mercurial.i18n import _
-from mercurial.node import bin, hex, nullid, short
+from mercurial.node import bin, hex, short
 from mercurial.pycompat import (
     getattr,
     setattr,
@@ -154,7 +154,7 @@
         rev = rlog.rev(node)
     else:
         node = rlog.node(rev)
-    if node == nullid:
+    if node == rlog.nullid:
         return False
     flags = rlog.flags(rev)
     return bool(flags & revlog.REVIDX_EXTSTORED)
diff --git a/hgext/mq.py b/hgext/mq.py
--- a/hgext/mq.py
+++ b/hgext/mq.py
@@ -73,7 +73,6 @@
 from mercurial.node import (
     bin,
     hex,
-    nullid,
     nullrev,
     short,
 )
@@ -899,13 +898,13 @@
         """
         if rev is None:
             (p1, p2) = repo.dirstate.parents()
-            if p2 == nullid:
+            if p2 == repo.nullid:
                 return p1
             if not self.applied:
                 return None
             return self.applied[-1].node
         p1, p2 = repo.changelog.parents(rev)
-        if p2 != nullid and p2 in [x.node for x in self.applied]:
+        if p2 != repo.nullid and p2 in [x.node for x in self.applied]:
             return p2
         return p1
 
@@ -1582,7 +1581,7 @@
             for hs in repo.branchmap().iterheads():
                 heads.extend(hs)
             if not heads:
-                heads = [nullid]
+                heads = [repo.nullid]
             if repo.dirstate.p1() not in heads and not exact:
                 self.ui.status(_(b"(working directory not at a head)\n"))
 
@@ -1845,7 +1844,7 @@
                         fctx = ctx[f]
                         repo.wwrite(f, fctx.data(), fctx.flags())
                         repo.dirstate.normal(f)
-                    repo.setparents(qp, nullid)
+                    repo.setparents(qp, repo.nullid)
             for patch in reversed(self.applied[start:end]):
                 self.ui.status(_(b"popping %s\n") % patch.name)
             del self.applied[start:end]
diff --git a/hgext/narrow/narrowbundle2.py b/hgext/narrow/narrowbundle2.py
--- a/hgext/narrow/narrowbundle2.py
+++ b/hgext/narrow/narrowbundle2.py
@@ -11,7 +11,6 @@
 import struct
 
 from mercurial.i18n import _
-from mercurial.node import nullid
 from mercurial import (
     bundle2,
     changegroup,
@@ -87,7 +86,7 @@
             raise error.Abort(_(b'depth must be positive, got %d') % depth)
 
     heads = set(heads or repo.heads())
-    common = set(common or [nullid])
+    common = set(common or [repo.nullid])
 
     visitnodes, relevant_nodes, ellipsisroots = exchange._computeellipsis(
         repo, common, heads, set(), match, depth=depth
@@ -115,7 +114,7 @@
 def generate_ellipses_bundle2_for_widening(
     bundler, repo, oldmatch, newmatch, version, common, known,
 ):
-    common = set(common or [nullid])
+    common = set(common or [repo.nullid])
     # Steps:
     # 1. Send kill for "$known & ::common"
     #
diff --git a/hgext/narrow/narrowcommands.py b/hgext/narrow/narrowcommands.py
--- a/hgext/narrow/narrowcommands.py
+++ b/hgext/narrow/narrowcommands.py
@@ -10,6 +10,10 @@
 import os
 
 from mercurial.i18n import _
+from mercurial.node import (
+    hex,
+    short,
+)
 from mercurial import (
     bundle2,
     cmdutil,
@@ -21,7 +25,6 @@
     extensions,
     hg,
     narrowspec,
-    node,
     pathutil,
     pycompat,
     registrar,
@@ -184,9 +187,9 @@
     # we have all the nodes
     if wireprototypes.ELLIPSESCAP1 in pullop.remote.capabilities():
         kwargs[b'known'] = [
-            node.hex(ctx.node())
+            hex(ctx.node())
             for ctx in repo.set(b'::%ln', pullop.common)
-            if ctx.node() != node.nullid
+            if ctx.node() != repo.nullid
         ]
         if not kwargs[b'known']:
             # Mercurial serializes an empty list as '' and deserializes it as
@@ -239,10 +242,10 @@
         maxnodes = 10
         if ui.verbose or len(visibletostrip) <= maxnodes:
             for n in visibletostrip:
-                ui.status(b'%s\n' % node.short(n))
+                ui.status(b'%s\n' % short(n))
         else:
             for n in visibletostrip[:maxnodes]:
-                ui.status(b'%s\n' % node.short(n))
+                ui.status(b'%s\n' % short(n))
             ui.status(
                 _(b'...and %d more, use --verbose to list all\n')
                 % (len(visibletostrip) - maxnodes)
@@ -362,7 +365,7 @@
             ds = repo.dirstate
             p1, p2 = ds.p1(), ds.p2()
             with ds.parentchange():
-                ds.setparents(node.nullid, node.nullid)
+                ds.setparents(repo.nullid, repo.nullid)
         if isoldellipses:
             with wrappedextraprepare:
                 exchange.pull(repo, remote, heads=common)
@@ -372,7 +375,7 @@
                 known = [
                     ctx.node()
                     for ctx in repo.set(b'::%ln', common)
-                    if ctx.node() != node.nullid
+                    if ctx.node() != repo.nullid
                 ]
             with remote.commandexecutor() as e:
                 bundle = e.callcommand(
diff --git a/hgext/patchbomb.py b/hgext/patchbomb.py
--- a/hgext/patchbomb.py
+++ b/hgext/patchbomb.py
@@ -82,6 +82,7 @@
 import socket
 
 from mercurial.i18n import _
+from mercurial.node import bin
 from mercurial.pycompat import open
 from mercurial import (
     cmdutil,
@@ -91,7 +92,6 @@
     formatter,
     hg,
     mail,
-    node as nodemod,
     patch,
     pycompat,
     registrar,
@@ -287,7 +287,7 @@
         p = mail.mimetextpatch(
             b'\n'.join(patchlines), 'x-patch', opts.get(b'test')
         )
-        binnode = nodemod.bin(node)
+        binnode = bin(node)
         # if node is mq patch, it will have the patch file's name as a tag
         if not patchname:
             patchtags = [
diff --git a/hgext/phabricator.py b/hgext/phabricator.py
--- a/hgext/phabricator.py
+++ b/hgext/phabricator.py
@@ -54,7 +54,7 @@
 import operator
 import re
 
-from mercurial.node import bin, nullid, short
+from mercurial.node import bin, short
 from mercurial.i18n import _
 from mercurial.pycompat import getattr
 from mercurial.thirdparty import attr
@@ -526,7 +526,7 @@
                 tags.tag(
                     repo,
                     tagname,
-                    nullid,
+                    repo.nullid,
                     message=None,
                     user=None,
                     date=None,
@@ -1545,7 +1545,7 @@
                         tags.tag(
                             repo,
                             tagname,
-                            nullid,
+                            repo.nullid,
                             message=None,
                             user=None,
                             date=None,
diff --git a/hgext/rebase.py b/hgext/rebase.py
--- a/hgext/rebase.py
+++ b/hgext/rebase.py
@@ -23,6 +23,7 @@
 from mercurial.node import (
     nullrev,
     short,
+    wdirrev,
 )
 from mercurial.pycompat import open
 from mercurial import (
@@ -37,7 +38,6 @@
     merge as mergemod,
     mergestate as mergestatemod,
     mergeutil,
-    node as nodemod,
     obsolete,
     obsutil,
     patch,
@@ -1365,7 +1365,7 @@
                 )
             return None
 
-    if nodemod.wdirrev in rebaseset:
+    if wdirrev in rebaseset:
         raise error.Abort(_(b'cannot rebase the working copy'))
     rebasingwcp = repo[b'.'].rev() in rebaseset
     ui.log(
diff --git a/hgext/releasenotes.py b/hgext/releasenotes.py
--- a/hgext/releasenotes.py
+++ b/hgext/releasenotes.py
@@ -18,13 +18,13 @@
 import re
 
 from mercurial.i18n import _
+from mercurial.node import hex
 from mercurial.pycompat import open
 from mercurial import (
     cmdutil,
     config,
     error,
     minirst,
-    node,
     pycompat,
     registrar,
     scmutil,
@@ -381,7 +381,7 @@
             if not paragraphs:
                 repo.ui.warn(
                     _(b"error parsing releasenotes for revision: '%s'\n")
-                    % node.hex(ctx.node())
+                    % hex(ctx.node())
                 )
             if title:
                 notes.addtitleditem(directive, title, paragraphs)
diff --git a/hgext/remotefilelog/__init__.py b/hgext/remotefilelog/__init__.py
--- a/hgext/remotefilelog/__init__.py
+++ b/hgext/remotefilelog/__init__.py
@@ -130,7 +130,10 @@
 import time
 import traceback
 
-from mercurial.node import hex
+from mercurial.node import (
+    hex,
+    wdirrev,
+)
 from mercurial.i18n import _
 from mercurial.pycompat import open
 from mercurial import (
@@ -150,7 +153,6 @@
     match as matchmod,
     merge,
     mergestate as mergestatemod,
-    node as nodemod,
     patch,
     pycompat,
     registrar,
@@ -1092,7 +1094,7 @@
     if isenabled(repo):
         allfiles = []
         for rev, match in revmatches:
-            if rev == nodemod.wdirrev or rev is None:
+            if rev == wdirrev or rev is None:
                 continue
             ctx = repo[rev]
             mf = ctx.manifest()
diff --git a/hgext/remotefilelog/basepack.py b/hgext/remotefilelog/basepack.py
--- a/hgext/remotefilelog/basepack.py
+++ b/hgext/remotefilelog/basepack.py
@@ -8,12 +8,12 @@
 import time
 
 from mercurial.i18n import _
+from mercurial.node import hex
 from mercurial.pycompat import (
     getattr,
     open,
 )
 from mercurial import (
-    node as nodemod,
     policy,
     pycompat,
     util,
@@ -429,7 +429,7 @@
             return
 
         try:
-            sha = nodemod.hex(self.sha.digest())
+            sha = hex(self.sha.digest())
             self.packfp.close()
             self.writeindex()
 
diff --git a/hgext/remotefilelog/contentstore.py b/hgext/remotefilelog/contentstore.py
--- a/hgext/remotefilelog/contentstore.py
+++ b/hgext/remotefilelog/contentstore.py
@@ -2,7 +2,10 @@
 
 import threading
 
-from mercurial.node import hex, nullid
+from mercurial.node import (
+    hex,
+    sha1nodeconstants,
+)
 from mercurial.pycompat import getattr
 from mercurial import (
     mdiff,
@@ -56,7 +59,7 @@
         """
         chain = self.getdeltachain(name, node)
 
-        if chain[-1][ChainIndicies.BASENODE] != nullid:
+        if chain[-1][ChainIndicies.BASENODE] != sha1nodeconstants.nullid:
             # If we didn't receive a full chain, throw
             raise KeyError((name, hex(node)))
 
@@ -94,7 +97,7 @@
         deltabasenode.
         """
         chain = self._getpartialchain(name, node)
-        while chain[-1][ChainIndicies.BASENODE] != nullid:
+        while chain[-1][ChainIndicies.BASENODE] != sha1nodeconstants.nullid:
             x, x, deltabasename, deltabasenode, x = chain[-1]
             try:
                 morechain = self._getpartialchain(deltabasename, deltabasenode)
@@ -189,7 +192,12 @@
         # Since remotefilelog content stores only contain full texts, just
         # return that.
         revision = self.get(name, node)
-        return revision, name, nullid, self.getmeta(name, node)
+        return (
+            revision,
+            name,
+            sha1nodeconstants.nullid,
+            self.getmeta(name, node),
+        )
 
     def getdeltachain(self, name, node):
         # Since remotefilelog content stores just contain full texts, we return
@@ -197,7 +205,7 @@
         # The nullid in the deltabasenode slot indicates that the revision is a
         # fulltext.
         revision = self.get(name, node)
-        return [(name, node, None, nullid, revision)]
+        return [(name, node, None, sha1nodeconstants.nullid, revision)]
 
     def getmeta(self, name, node):
         self._sanitizemetacache()
@@ -239,7 +247,12 @@
 
     def getdelta(self, name, node):
         revision = self.get(name, node)
-        return revision, name, nullid, self._shared.getmeta(name, node)
+        return (
+            revision,
+            name,
+            sha1nodeconstants.nullid,
+            self._shared.getmeta(name, node),
+        )
 
     def getdeltachain(self, name, node):
         # Since our remote content stores just contain full texts, we return a
@@ -247,7 +260,7 @@
         # The nullid in the deltabasenode slot indicates that the revision is a
         # fulltext.
         revision = self.get(name, node)
-        return [(name, node, None, nullid, revision)]
+        return [(name, node, None, sha1nodeconstants.nullid, revision)]
 
     def getmeta(self, name, node):
         self._fileservice.prefetch(
@@ -278,11 +291,11 @@
 
     def getdelta(self, name, node):
         revision = self.get(name, node)
-        return revision, name, nullid, self.getmeta(name, node)
+        return revision, name, self._cl.nullid, self.getmeta(name, node)
 
     def getdeltachain(self, name, node):
         revision = self.get(name, node)
-        return [(name, node, None, nullid, revision)]
+        return [(name, node, None, self._cl.nullid, revision)]
 
     def getmeta(self, name, node):
         rl = self._revlog(name)
@@ -306,9 +319,9 @@
             missing.discard(ancnode)
 
             p1, p2 = rl.parents(ancnode)
-            if p1 != nullid and p1 not in known:
+            if p1 != self._cl.nullid and p1 not in known:
                 missing.add(p1)
-            if p2 != nullid and p2 not in known:
+            if p2 != self._cl.nullid and p2 not in known:
                 missing.add(p2)
 
             linknode = self._cl.node(rl.linkrev(ancrev))
diff --git a/hgext/remotefilelog/datapack.py b/hgext/remotefilelog/datapack.py
--- a/hgext/remotefilelog/datapack.py
+++ b/hgext/remotefilelog/datapack.py
@@ -3,7 +3,10 @@
 import struct
 import zlib
 
-from mercurial.node import hex, nullid
+from mercurial.node import (
+    hex,
+    sha1nodeconstants,
+)
 from mercurial.i18n import _
 from mercurial import (
     pycompat,
@@ -458,7 +461,7 @@
         rawindex = b''
         fmt = self.INDEXFORMAT
         for node, deltabase, offset, size in entries:
-            if deltabase == nullid:
+            if deltabase == sha1nodeconstants.nullid:
                 deltabaselocation = FULLTEXTINDEXMARK
             else:
                 # Instead of storing the deltabase node in the index, let's
diff --git a/hgext/remotefilelog/debugcommands.py b/hgext/remotefilelog/debugcommands.py
--- a/hgext/remotefilelog/debugcommands.py
+++ b/hgext/remotefilelog/debugcommands.py
@@ -9,7 +9,12 @@
 import os
 import zlib
 
-from mercurial.node import bin, hex, nullid, short
+from mercurial.node import (
+    bin,
+    hex,
+    sha1nodeconstants,
+    short,
+)
 from mercurial.i18n import _
 from mercurial.pycompat import open
 from mercurial import (
@@ -53,9 +58,9 @@
             _(b"%s => %s  %s  %s  %s\n")
             % (short(node), short(p1), short(p2), short(linknode), copyfrom)
         )
-        if p1 != nullid:
+        if p1 != sha1nodeconstants.nullid:
             queue.append(p1)
-        if p2 != nullid:
+        if p2 != sha1nodeconstants.nullid:
             queue.append(p2)
 
 
@@ -148,7 +153,7 @@
             try:
                 pp = r.parents(node)
             except Exception:
-                pp = [nullid, nullid]
+                pp = [repo.nullid, repo.nullid]
             ui.write(
                 b"% 6d % 9d % 7d % 6d % 7d %s %s %s\n"
                 % (
@@ -193,7 +198,7 @@
         node = r.node(i)
         pp = r.parents(node)
         ui.write(b"\t%d -> %d\n" % (r.rev(pp[0]), i))
-        if pp[1] != nullid:
+        if pp[1] != repo.nullid:
             ui.write(b"\t%d -> %d\n" % (r.rev(pp[1]), i))
     ui.write(b"}\n")
 
@@ -208,7 +213,7 @@
             filepath = os.path.join(root, file)
             size, firstnode, mapping = parsefileblob(filepath, decompress)
             for p1, p2, linknode, copyfrom in pycompat.itervalues(mapping):
-                if linknode == nullid:
+                if linknode == sha1nodeconstants.nullid:
                     actualpath = os.path.relpath(root, path)
                     key = fileserverclient.getcachekey(
                         b"reponame", actualpath, file
@@ -367,7 +372,7 @@
         current = node
         deltabase = bases[current]
 
-        while deltabase != nullid:
+        while deltabase != sha1nodeconstants.nullid:
             if deltabase not in nodes:
                 ui.warn(
                     (
@@ -393,7 +398,7 @@
             deltabase = bases[current]
         # Since ``node`` begins a valid chain, reset/memoize its base to nullid
         # so we don't traverse it again.
-        bases[node] = nullid
+        bases[node] = sha1nodeconstants.nullid
     return failures
 
 
diff --git a/hgext/remotefilelog/fileserverclient.py b/hgext/remotefilelog/fileserverclient.py
--- a/hgext/remotefilelog/fileserverclient.py
+++ b/hgext/remotefilelog/fileserverclient.py
@@ -14,7 +14,7 @@
 import zlib
 
 from mercurial.i18n import _
-from mercurial.node import bin, hex, nullid
+from mercurial.node import bin, hex
 from mercurial import (
     error,
     node,
@@ -602,9 +602,13 @@
 
         # partition missing nodes into nullid and not-nullid so we can
         # warn about this filtering potentially shadowing bugs.
-        nullids = len([None for unused, id in missingids if id == nullid])
+        nullids = len(
+            [None for unused, id in missingids if id == self.repo.nullid]
+        )
         if nullids:
-            missingids = [(f, id) for f, id in missingids if id != nullid]
+            missingids = [
+                (f, id) for f, id in missingids if id != self.repo.nullid
+            ]
             repo.ui.develwarn(
                 (
                     b'remotefilelog not fetching %d null revs'
diff --git a/hgext/remotefilelog/historypack.py b/hgext/remotefilelog/historypack.py
--- a/hgext/remotefilelog/historypack.py
+++ b/hgext/remotefilelog/historypack.py
@@ -2,7 +2,10 @@
 
 import struct
 
-from mercurial.node import hex, nullid
+from mercurial.node import (
+    hex,
+    sha1nodeconstants,
+)
 from mercurial import (
     pycompat,
     util,
@@ -147,9 +150,9 @@
                 pending.remove(ancnode)
                 p1node = entry[ANC_P1NODE]
                 p2node = entry[ANC_P2NODE]
-                if p1node != nullid and p1node not in known:
+                if p1node != sha1nodeconstants.nullid and p1node not in known:
                     pending.add(p1node)
-                if p2node != nullid and p2node not in known:
+                if p2node != sha1nodeconstants.nullid and p2node not in known:
                     pending.add(p2node)
 
                 yield (ancnode, p1node, p2node, entry[ANC_LINKNODE], copyfrom)
@@ -457,9 +460,9 @@
             def parentfunc(node):
                 x, p1, p2, x, x, x = entrymap[node]
                 parents = []
-                if p1 != nullid:
+                if p1 != sha1nodeconstants.nullid:
                     parents.append(p1)
-                if p2 != nullid:
+                if p2 != sha1nodeconstants.nullid:
                     parents.append(p2)
                 return parents
 
diff --git a/hgext/remotefilelog/metadatastore.py b/hgext/remotefilelog/metadatastore.py
--- a/hgext/remotefilelog/metadatastore.py
+++ b/hgext/remotefilelog/metadatastore.py
@@ -1,6 +1,9 @@
 from __future__ import absolute_import
 
-from mercurial.node import hex, nullid
+from mercurial.node import (
+    hex,
+    sha1nodeconstants,
+)
 from . import (
     basestore,
     shallowutil,
@@ -51,9 +54,9 @@
                     missing.append((name, node))
                     continue
                 p1, p2, linknode, copyfrom = value
-                if p1 != nullid and p1 not in known:
+                if p1 != sha1nodeconstants.nullid and p1 not in known:
                     queue.append((copyfrom or curname, p1))
-                if p2 != nullid and p2 not in known:
+                if p2 != sha1nodeconstants.nullid and p2 not in known:
                     queue.append((curname, p2))
             return missing
 
diff --git a/hgext/remotefilelog/remotefilectx.py b/hgext/remotefilelog/remotefilectx.py
--- a/hgext/remotefilelog/remotefilectx.py
+++ b/hgext/remotefilelog/remotefilectx.py
@@ -9,7 +9,7 @@
 import collections
 import time
 
-from mercurial.node import bin, hex, nullid, nullrev
+from mercurial.node import bin, hex, nullrev
 from mercurial import (
     ancestor,
     context,
@@ -35,7 +35,7 @@
         ancestormap=None,
     ):
         if fileid == nullrev:
-            fileid = nullid
+            fileid = repo.nullid
         if fileid and len(fileid) == 40:
             fileid = bin(fileid)
         super(remotefilectx, self).__init__(
@@ -78,7 +78,7 @@
 
     @propertycache
     def _linkrev(self):
-        if self._filenode == nullid:
+        if self._filenode == self._repo.nullid:
             return nullrev
 
         ancestormap = self.ancestormap()
@@ -174,7 +174,7 @@
 
         p1, p2, linknode, copyfrom = ancestormap[self._filenode]
         results = []
-        if p1 != nullid:
+        if p1 != repo.nullid:
             path = copyfrom or self._path
             flog = repo.file(path)
             p1ctx = remotefilectx(
@@ -183,7 +183,7 @@
             p1ctx._descendantrev = self.rev()
             results.append(p1ctx)
 
-        if p2 != nullid:
+        if p2 != repo.nullid:
             path = self._path
             flog = repo.file(path)
             p2ctx = remotefilectx(
@@ -504,25 +504,25 @@
             if renamed:
                 p1 = renamed
             else:
-                p1 = (path, pcl[0]._manifest.get(path, nullid))
+                p1 = (path, pcl[0]._manifest.get(path, self._repo.nullid))
 
-            p2 = (path, nullid)
+            p2 = (path, self._repo.nullid)
             if len(pcl) > 1:
                 p2 = (path, pcl[1]._manifest.get(path, nullid))
 
             m = {}
-            if p1[1] != nullid:
+            if p1[1] != self._repo.nullid:
                 p1ctx = self._repo.filectx(p1[0], fileid=p1[1])
                 m.update(p1ctx.filelog().ancestormap(p1[1]))
 
-            if p2[1] != nullid:
+            if p2[1] != self._repo.nullid:
                 p2ctx = self._repo.filectx(p2[0], fileid=p2[1])
                 m.update(p2ctx.filelog().ancestormap(p2[1]))
 
             copyfrom = b''
             if renamed:
                 copyfrom = renamed[0]
-            m[None] = (p1[1], p2[1], nullid, copyfrom)
+            m[None] = (p1[1], p2[1], self._repo.nullid, copyfrom)
             self._ancestormap = m
 
         return self._ancestormap
diff --git a/hgext/remotefilelog/remotefilelog.py b/hgext/remotefilelog/remotefilelog.py
--- a/hgext/remotefilelog/remotefilelog.py
+++ b/hgext/remotefilelog/remotefilelog.py
@@ -10,12 +10,7 @@
 import collections
 import os
 
-from mercurial.node import (
-    bin,
-    nullid,
-    wdirfilenodeids,
-    wdirid,
-)
+from mercurial.node import bin
 from mercurial.i18n import _
 from mercurial import (
     ancestor,
@@ -100,7 +95,7 @@
 
         pancestors = {}
         queue = []
-        if realp1 != nullid:
+        if realp1 != self.repo.nullid:
             p1flog = self
             if copyfrom:
                 p1flog = remotefilelog(self.opener, copyfrom, self.repo)
@@ -108,7 +103,7 @@
             pancestors.update(p1flog.ancestormap(realp1))
             queue.append(realp1)
             visited.add(realp1)
-        if p2 != nullid:
+        if p2 != self.repo.nullid:
             pancestors.update(self.ancestormap(p2))
             queue.append(p2)
             visited.add(p2)
@@ -129,10 +124,10 @@
                 pacopyfrom,
             )
 
-            if pa1 != nullid and pa1 not in visited:
+            if pa1 != self.repo.nullid and pa1 not in visited:
                 queue.append(pa1)
                 visited.add(pa1)
-            if pa2 != nullid and pa2 not in visited:
+            if pa2 != self.repo.nullid and pa2 not in visited:
                 queue.append(pa2)
                 visited.add(pa2)
 
@@ -238,7 +233,7 @@
         returns True if text is different than what is stored.
         """
 
-        if node == nullid:
+        if node == self.repo.nullid:
             return True
 
         nodetext = self.read(node)
@@ -275,13 +270,13 @@
         return store.getmeta(self.filename, node).get(constants.METAKEYFLAG, 0)
 
     def parents(self, node):
-        if node == nullid:
-            return nullid, nullid
+        if node == self.repo.nullid:
+            return self.repo.nullid, self.repo.nullid
 
         ancestormap = self.repo.metadatastore.getancestors(self.filename, node)
         p1, p2, linknode, copyfrom = ancestormap[node]
         if copyfrom:
-            p1 = nullid
+            p1 = self.repo.nullid
 
         return p1, p2
 
@@ -316,8 +311,8 @@
             if prevnode is None:
                 basenode = prevnode = p1
             if basenode == node:
-                basenode = nullid
-            if basenode != nullid:
+                basenode = self.repo.nullid
+            if basenode != self.repo.nullid:
                 revision = None
                 delta = self.revdiff(basenode, node)
             else:
@@ -377,13 +372,16 @@
         this is generally only used for bundling and communicating with vanilla
         hg clients.
         """
-        if node == nullid:
+        if node == self.repo.nullid:
             return b""
         if len(node) != 20:
             raise error.LookupError(
                 node, self.filename, _(b'invalid revision input')
             )
-        if node == wdirid or node in wdirfilenodeids:
+        if (
+            node == self.repo.nodeconstants.wdirid
+            or node in self.repo.nodeconstants.wdirfilenodeids
+        ):
             raise error.WdirUnsupported
 
         store = self.repo.contentstore
@@ -429,8 +427,8 @@
         return self.repo.metadatastore.getancestors(self.filename, node)
 
     def ancestor(self, a, b):
-        if a == nullid or b == nullid:
-            return nullid
+        if a == self.repo.nullid or b == self.repo.nullid:
+            return self.repo.nullid
 
         revmap, parentfunc = self._buildrevgraph(a, b)
         nodemap = {v: k for (k, v) in pycompat.iteritems(revmap)}
@@ -439,13 +437,13 @@
         if ancs:
             # choose a consistent winner when there's a tie
             return min(map(nodemap.__getitem__, ancs))
-        return nullid
+        return self.repo.nullid
 
     def commonancestorsheads(self, a, b):
         """calculate all the heads of the common ancestors of nodes a and b"""
 
-        if a == nullid or b == nullid:
-            return nullid
+        if a == self.repo.nullid or b == self.repo.nullid:
+            return self.repo.nullid
 
         revmap, parentfunc = self._buildrevgraph(a, b)
         nodemap = {v: k for (k, v) in pycompat.iteritems(revmap)}
@@ -469,10 +467,10 @@
                 p1, p2, linknode, copyfrom = pdata
                 # Don't follow renames (copyfrom).
                 # remotefilectx.ancestor does that.
-                if p1 != nullid and not copyfrom:
+                if p1 != self.repo.nullid and not copyfrom:
                     parents.append(p1)
                     allparents.add(p1)
-                if p2 != nullid:
+                if p2 != self.repo.nullid:
                     parents.append(p2)
                     allparents.add(p2)
 
diff --git a/hgext/remotefilelog/remotefilelogserver.py b/hgext/remotefilelog/remotefilelogserver.py
--- a/hgext/remotefilelog/remotefilelogserver.py
+++ b/hgext/remotefilelog/remotefilelogserver.py
@@ -13,7 +13,7 @@
 import zlib
 
 from mercurial.i18n import _
-from mercurial.node import bin, hex, nullid
+from mercurial.node import bin, hex
 from mercurial.pycompat import open
 from mercurial import (
     changegroup,
@@ -242,7 +242,7 @@
     filecachepath = os.path.join(cachepath, path, hex(node))
     if not os.path.exists(filecachepath) or os.path.getsize(filecachepath) == 0:
         filectx = repo.filectx(path, fileid=node)
-        if filectx.node() == nullid:
+        if filectx.node() == repo.nullid:
             repo.changelog = changelog.changelog(repo.svfs)
             filectx = repo.filectx(path, fileid=node)
 
@@ -285,7 +285,7 @@
     """
     flog = repo.file(path)
     heads = flog.heads()
-    return b'\n'.join((hex(head) for head in heads if head != nullid))
+    return b'\n'.join((hex(head) for head in heads if head != repo.nullid))
 
 
 def getfile(repo, proto, file, node):
@@ -303,7 +303,7 @@
     if not cachepath:
         cachepath = os.path.join(repo.path, b"remotefilelogcache")
     node = bin(node.strip())
-    if node == nullid:
+    if node == repo.nullid:
         return b'0\0'
     return b'0\0' + _loadfileblob(repo, cachepath, file, node)
 
@@ -329,7 +329,7 @@
                 break
 
             node = bin(request[:40])
-            if node == nullid:
+            if node == repo.nullid:
                 yield b'0\n'
                 continue
 
@@ -382,8 +382,8 @@
         ancestortext = b""
         for ancestorctx in ancestors:
             parents = ancestorctx.parents()
-            p1 = nullid
-            p2 = nullid
+            p1 = repo.nullid
+            p2 = repo.nullid
             if len(parents) > 0:
                 p1 = parents[0].filenode()
             if len(parents) > 1:
diff --git a/hgext/remotefilelog/repack.py b/hgext/remotefilelog/repack.py
--- a/hgext/remotefilelog/repack.py
+++ b/hgext/remotefilelog/repack.py
@@ -4,10 +4,7 @@
 import time
 
 from mercurial.i18n import _
-from mercurial.node import (
-    nullid,
-    short,
-)
+from mercurial.node import short
 from mercurial import (
     encoding,
     error,
@@ -587,7 +584,7 @@
         # Create one contiguous chain and reassign deltabases.
         for i, node in enumerate(orphans):
             if i == 0:
-                deltabases[node] = (nullid, 0)
+                deltabases[node] = (self.repo.nullid, 0)
             else:
                 parent = orphans[i - 1]
                 deltabases[node] = (parent, deltabases[parent][1] + 1)
@@ -677,8 +674,8 @@
                 # of immediate child
                 deltatuple = deltabases.get(node, None)
                 if deltatuple is None:
-                    deltabase, chainlen = nullid, 0
-                    deltabases[node] = (nullid, 0)
+                    deltabase, chainlen = self.repo.nullid, 0
+                    deltabases[node] = (self.repo.nullid, 0)
                     nobase.add(node)
                 else:
                     deltabase, chainlen = deltatuple
@@ -693,7 +690,7 @@
                     # file was copied from elsewhere. So don't attempt to do any
                     # deltas with the other file.
                     if copyfrom:
-                        p1 = nullid
+                        p1 = self.repo.nullid
 
                     if chainlen < maxchainlen:
                         # Record this child as the delta base for its parents.
@@ -701,9 +698,9 @@
                         # many children, and this will only choose the last one.
                         # TODO: record all children and try all deltas to find
                         # best
-                        if p1 != nullid:
+                        if p1 != self.repo.nullid:
                             deltabases[p1] = (node, chainlen + 1)
-                        if p2 != nullid:
+                        if p2 != self.repo.nullid:
                             deltabases[p2] = (node, chainlen + 1)
 
             # experimental config: repack.chainorphansbysize
@@ -720,7 +717,7 @@
                 # TODO: Optimize the deltachain fetching. Since we're
                 # iterating over the different version of the file, we may
                 # be fetching the same deltachain over and over again.
-                if deltabase != nullid:
+                if deltabase != self.repo.nullid:
                     deltaentry = self.data.getdelta(filename, node)
                     delta, deltabasename, origdeltabase, meta = deltaentry
                     size = meta.get(constants.METAKEYSIZE)
@@ -792,9 +789,9 @@
                     # If copyfrom == filename, it means the copy history
                     # went to come other file, then came back to this one, so we
                     # should continue processing it.
-                    if p1 != nullid and copyfrom != filename:
+                    if p1 != self.repo.nullid and copyfrom != filename:
                         dontprocess.add(p1)
-                    if p2 != nullid:
+                    if p2 != self.repo.nullid:
                         dontprocess.add(p2)
                     continue
 
@@ -815,9 +812,9 @@
         def parentfunc(node):
             p1, p2, linknode, copyfrom = ancestors[node]
             parents = []
-            if p1 != nullid:
+            if p1 != self.repo.nullid:
                 parents.append(p1)
-            if p2 != nullid:
+            if p2 != self.repo.nullid:
                 parents.append(p2)
             return parents
 
diff --git a/hgext/remotefilelog/shallowbundle.py b/hgext/remotefilelog/shallowbundle.py
--- a/hgext/remotefilelog/shallowbundle.py
+++ b/hgext/remotefilelog/shallowbundle.py
@@ -7,7 +7,7 @@
 from __future__ import absolute_import
 
 from mercurial.i18n import _
-from mercurial.node import bin, hex, nullid
+from mercurial.node import bin, hex
 from mercurial import (
     bundlerepo,
     changegroup,
@@ -129,7 +129,7 @@
 
     def nodechunk(self, revlog, node, prevnode, linknode):
         prefix = b''
-        if prevnode == nullid:
+        if prevnode == revlog.nullid:
             delta = revlog.rawdata(node)
             prefix = mdiff.trivialdiffheader(len(delta))
         else:
@@ -229,7 +229,7 @@
     processed = set()
 
     def available(f, node, depf, depnode):
-        if depnode != nullid and (depf, depnode) not in processed:
+        if depnode != repo.nullid and (depf, depnode) not in processed:
             if not (depf, depnode) in revisiondatas:
                 # It's not in the changegroup, assume it's already
                 # in the repo
@@ -251,7 +251,7 @@
         dependents = [revisiondata[1], revisiondata[2], revisiondata[4]]
 
         for dependent in dependents:
-            if dependent == nullid or (f, dependent) in revisiondatas:
+            if dependent == repo.nullid or (f, dependent) in revisiondatas:
                 continue
             prefetchfiles.append((f, hex(dependent)))
 
@@ -290,7 +290,7 @@
                 continue
 
         for p in [p1, p2]:
-            if p != nullid:
+            if p != repo.nullid:
                 if not available(f, node, f, p):
                     continue
 
diff --git a/hgext/remotefilelog/shallowrepo.py b/hgext/remotefilelog/shallowrepo.py
--- a/hgext/remotefilelog/shallowrepo.py
+++ b/hgext/remotefilelog/shallowrepo.py
@@ -9,7 +9,7 @@
 import os
 
 from mercurial.i18n import _
-from mercurial.node import hex, nullid, nullrev
+from mercurial.node import hex, nullrev
 from mercurial import (
     encoding,
     error,
@@ -206,8 +206,8 @@
                 m1 = ctx.p1().manifest()
                 files = []
                 for f in ctx.modified() + ctx.added():
-                    fparent1 = m1.get(f, nullid)
-                    if fparent1 != nullid:
+                    fparent1 = m1.get(f, self.nullid)
+                    if fparent1 != self.nullid:
                         files.append((f, hex(fparent1)))
                 self.fileservice.prefetch(files)
             return super(shallowrepository, self).commitctx(
diff --git a/hgext/remotefilelog/shallowutil.py b/hgext/remotefilelog/shallowutil.py
--- a/hgext/remotefilelog/shallowutil.py
+++ b/hgext/remotefilelog/shallowutil.py
@@ -15,9 +15,9 @@
 
 from mercurial.i18n import _
 from mercurial.pycompat import open
+from mercurial.node import hex
 from mercurial import (
     error,
-    node,
     pycompat,
     revlog,
     util,
@@ -39,12 +39,12 @@
 
 
 def getcachekey(reponame, file, id):
-    pathhash = node.hex(hashutil.sha1(file).digest())
+    pathhash = hex(hashutil.sha1(file).digest())
     return os.path.join(reponame, pathhash[:2], pathhash[2:], id)
 
 
 def getlocalkey(file, id):
-    pathhash = node.hex(hashutil.sha1(file).digest())
+    pathhash = hex(hashutil.sha1(file).digest())
     return os.path.join(pathhash, id)
 
 
diff --git a/hgext/split.py b/hgext/split.py
--- a/hgext/split.py
+++ b/hgext/split.py
@@ -10,11 +10,7 @@
 from __future__ import absolute_import
 
 from mercurial.i18n import _
-
-from mercurial.node import (
-    nullid,
-    short,
-)
+from mercurial.node import short
 
 from mercurial import (
     bookmarks,
@@ -78,7 +74,7 @@
         ctx = repo[rev]
         # Handle nullid specially here (instead of leaving for precheck()
         # below) so we get a nicer message and error code.
-        if rev is None or ctx.node() == nullid:
+        if rev is None or ctx.node() == repo.nullid:
             ui.status(_(b'nothing to split\n'))
             return 1
         if ctx.node() is None:
diff --git a/hgext/sqlitestore.py b/hgext/sqlitestore.py
--- a/hgext/sqlitestore.py
+++ b/hgext/sqlitestore.py
@@ -52,8 +52,8 @@
 
 from mercurial.i18n import _
 from mercurial.node import (
-    nullid,
     nullrev,
+    sha1nodeconstants,
     short,
 )
 from mercurial.thirdparty import attr
@@ -304,6 +304,7 @@
     """Implements storage for an individual tracked path."""
 
     def __init__(self, db, path, compression):
+        self.nullid = sha1nodeconstants.nullid
         self._db = db
         self._path = path
 
@@ -363,12 +364,12 @@
                 )
 
             if p1rev == nullrev:
-                p1node = nullid
+                p1node = sha1nodeconstants.nullid
             else:
                 p1node = self._revtonode[p1rev]
 
             if p2rev == nullrev:
-                p2node = nullid
+                p2node = sha1nodeconstants.nullid
             else:
                 p2node = self._revtonode[p2rev]
 
@@ -397,7 +398,7 @@
         return iter(pycompat.xrange(len(self._revisions)))
 
     def hasnode(self, node):
-        if node == nullid:
+        if node == sha1nodeconstants.nullid:
             return False
 
         return node in self._nodetorev
@@ -408,8 +409,8 @@
         )
 
     def parents(self, node):
-        if node == nullid:
-            return nullid, nullid
+        if node == sha1nodeconstants.nullid:
+            return sha1nodeconstants.nullid, sha1nodeconstants.nullid
 
         if node not in self._revisions:
             raise error.LookupError(node, self._path, _(b'no node'))
@@ -428,7 +429,7 @@
         return entry.p1rev, entry.p2rev
 
     def rev(self, node):
-        if node == nullid:
+        if node == sha1nodeconstants.nullid:
             return nullrev
 
         if node not in self._nodetorev:
@@ -438,7 +439,7 @@
 
     def node(self, rev):
         if rev == nullrev:
-            return nullid
+            return sha1nodeconstants.nullid
 
         if rev not in self._revtonode:
             raise IndexError(rev)
@@ -482,7 +483,7 @@
     def heads(self, start=None, stop=None):
         if start is None and stop is None:
             if not len(self):
-                return [nullid]
+                return [sha1nodeconstants.nullid]
 
         startrev = self.rev(start) if start is not None else nullrev
         stoprevs = {self.rev(n) for n in stop or []}
@@ -526,7 +527,7 @@
         return len(self.revision(node))
 
     def revision(self, node, raw=False, _verifyhash=True):
-        if node in (nullid, nullrev):
+        if node in (sha1nodeconstants.nullid, nullrev):
             return b''
 
         if isinstance(node, int):
@@ -592,7 +593,7 @@
                 b'unhandled value for nodesorder: %s' % nodesorder
             )
 
-        nodes = [n for n in nodes if n != nullid]
+        nodes = [n for n in nodes if n != sha1nodeconstants.nullid]
 
         if not nodes:
             return
@@ -689,12 +690,12 @@
                 raise SQLiteStoreError(b'unhandled revision flag')
 
             if maybemissingparents:
-                if p1 != nullid and not self.hasnode(p1):
-                    p1 = nullid
+                if p1 != sha1nodeconstants.nullid and not self.hasnode(p1):
+                    p1 = sha1nodeconstants.nullid
                     storeflags |= FLAG_MISSING_P1
 
-                if p2 != nullid and not self.hasnode(p2):
-                    p2 = nullid
+                if p2 != sha1nodeconstants.nullid and not self.hasnode(p2):
+                    p2 = sha1nodeconstants.nullid
                     storeflags |= FLAG_MISSING_P2
 
             baserev = self.rev(deltabase)
@@ -720,7 +721,10 @@
                 # Possibly reset parents to make them proper.
                 entry = self._revisions[node]
 
-                if entry.flags & FLAG_MISSING_P1 and p1 != nullid:
+                if (
+                    entry.flags & FLAG_MISSING_P1
+                    and p1 != sha1nodeconstants.nullid
+                ):
                     entry.p1node = p1
                     entry.p1rev = self._nodetorev[p1]
                     entry.flags &= ~FLAG_MISSING_P1
@@ -730,7 +734,10 @@
                         (self._nodetorev[p1], entry.flags, entry.rid),
                     )
 
-                if entry.flags & FLAG_MISSING_P2 and p2 != nullid:
+                if (
+                    entry.flags & FLAG_MISSING_P2
+                    and p2 != sha1nodeconstants.nullid
+                ):
                     entry.p2node = p2
                     entry.p2rev = self._nodetorev[p2]
                     entry.flags &= ~FLAG_MISSING_P2
@@ -745,7 +752,7 @@
                 empty = False
                 continue
 
-            if deltabase == nullid:
+            if deltabase == sha1nodeconstants.nullid:
                 text = mdiff.patch(b'', delta)
                 storedelta = None
             else:
@@ -992,7 +999,7 @@
             assert revisiondata is not None
             deltabase = p1
 
-            if deltabase == nullid:
+            if deltabase == sha1nodeconstants.nullid:
                 delta = revisiondata
             else:
                 delta = mdiff.textdiff(
@@ -1001,7 +1008,7 @@
 
         # File index stores a pointer to its delta and the parent delta.
         # The parent delta is stored via a pointer to the fileindex PK.
-        if deltabase == nullid:
+        if deltabase == sha1nodeconstants.nullid:
             baseid = None
         else:
             baseid = self._revisions[deltabase].rid
@@ -1035,12 +1042,12 @@
 
         rev = len(self)
 
-        if p1 == nullid:
+        if p1 == sha1nodeconstants.nullid:
             p1rev = nullrev
         else:
             p1rev = self._nodetorev[p1]
 
-        if p2 == nullid:
+        if p2 == sha1nodeconstants.nullid:
             p2rev = nullrev
         else:
             p2rev = self._nodetorev[p2]
diff --git a/hgext/transplant.py b/hgext/transplant.py
--- a/hgext/transplant.py
+++ b/hgext/transplant.py
@@ -18,6 +18,11 @@
 import os
 
 from mercurial.i18n import _
+from mercurial.node import (
+    bin,
+    hex,
+    short,
+)
 from mercurial.pycompat import open
 from mercurial import (
     bundlerepo,
@@ -28,11 +33,9 @@
     logcmdutil,
     match,
     merge,
-    node as nodemod,
     patch,
     pycompat,
     registrar,
-    revlog,
     revset,
     scmutil,
     smartset,
@@ -91,7 +94,7 @@
         abspath = os.path.join(self.path, self.transplantfile)
         if self.transplantfile and os.path.exists(abspath):
             for line in self.opener.read(self.transplantfile).splitlines():
-                lnode, rnode = map(revlog.bin, line.split(b':'))
+                lnode, rnode = map(bin, line.split(b':'))
                 list = self.transplants.setdefault(rnode, [])
                 list.append(transplantentry(lnode, rnode))
 
@@ -102,7 +105,7 @@
             fp = self.opener(self.transplantfile, b'w')
             for list in pycompat.itervalues(self.transplants):
                 for t in list:
-                    l, r = map(nodemod.hex, (t.lnode, t.rnode))
+                    l, r = map(hex, (t.lnode, t.rnode))
                     fp.write(l + b':' + r + b'\n')
             fp.close()
         self.dirty = False
@@ -125,6 +128,7 @@
 class transplanter(object):
     def __init__(self, ui, repo, opts):
         self.ui = ui
+        self.repo = repo
         self.path = repo.vfs.join(b'transplant')
         self.opener = vfsmod.vfs(self.path)
         self.transplants = transplants(
@@ -179,7 +183,7 @@
             tr = repo.transaction(b'transplant')
             for rev in revs:
                 node = revmap[rev]
-                revstr = b'%d:%s' % (rev, nodemod.short(node))
+                revstr = b'%d:%s' % (rev, short(node))
 
                 if self.applied(repo, node, p1):
                     self.ui.warn(
@@ -212,11 +216,11 @@
                         exchange.pull(repo, source.peer(), heads=[node])
 
                 skipmerge = False
-                if parents[1] != revlog.nullid:
+                if parents[1] != repo.nullid:
                     if not opts.get(b'parent'):
                         self.ui.note(
                             _(b'skipping merge changeset %d:%s\n')
-                            % (rev, nodemod.short(node))
+                            % (rev, short(node))
                         )
                         skipmerge = True
                     else:
@@ -224,7 +228,7 @@
                         if parent not in parents:
                             raise error.Abort(
                                 _(b'%s is not a parent of %s')
-                                % (nodemod.short(parent), nodemod.short(node))
+                                % (short(parent), short(node))
                             )
                 else:
                     parent = parents[0]
@@ -259,13 +263,12 @@
                             raise
                         if n and domerge:
                             self.ui.status(
-                                _(b'%s merged at %s\n')
-                                % (revstr, nodemod.short(n))
+                                _(b'%s merged at %s\n') % (revstr, short(n))
                             )
                         elif n:
                             self.ui.status(
                                 _(b'%s transplanted to %s\n')
-                                % (nodemod.short(node), nodemod.short(n))
+                                % (short(node), short(n))
                             )
                     finally:
                         if patchfile:
@@ -303,10 +306,7 @@
                     procutil.shellquote(headerfile),
                     procutil.shellquote(patchfile),
                 ),
-                environ={
-                    b'HGUSER': changelog[1],
-                    b'HGREVISION': nodemod.hex(node),
-                },
+                environ={b'HGUSER': changelog[1], b'HGREVISION': hex(node),},
                 onerr=error.Abort,
                 errprefix=_(b'filter failed'),
                 blockedtag=b'transplant_filter',
@@ -329,9 +329,9 @@
 
         if log:
             # we don't translate messages inserted into commits
-            message += b'\n(transplanted from %s)' % nodemod.hex(node)
+            message += b'\n(transplanted from %s)' % hex(node)
 
-        self.ui.status(_(b'applying %s\n') % nodemod.short(node))
+        self.ui.status(_(b'applying %s\n') % short(node))
         self.ui.note(b'%s %s\n%s\n' % (user, date, message))
 
         if not patchfile and not merge:
@@ -373,9 +373,7 @@
             editor=self.getcommiteditor(),
         )
         if not n:
-            self.ui.warn(
-                _(b'skipping emptied changeset %s\n') % nodemod.short(node)
-            )
+            self.ui.warn(_(b'skipping emptied changeset %s\n') % short(node))
             return None
         if not merge:
             self.transplants.set(n, node)
@@ -391,13 +389,11 @@
             n, node = self.recover(repo, source, opts)
             if n:
                 self.ui.status(
-                    _(b'%s transplanted as %s\n')
-                    % (nodemod.short(node), nodemod.short(n))
+                    _(b'%s transplanted as %s\n') % (short(node), short(n))
                 )
             else:
                 self.ui.status(
-                    _(b'%s skipped due to empty diff\n')
-                    % (nodemod.short(node),)
+                    _(b'%s skipped due to empty diff\n') % (short(node),)
                 )
         seriespath = os.path.join(self.path, b'series')
         if not os.path.exists(seriespath):
@@ -426,7 +422,7 @@
                 if parent not in parents:
                     raise error.Abort(
                         _(b'%s is not a parent of %s')
-                        % (nodemod.short(parent), nodemod.short(node))
+                        % (short(parent), short(node))
                     )
             else:
                 merge = True
@@ -437,7 +433,7 @@
             if p1 != parent:
                 raise error.Abort(
                     _(b'working directory not at transplant parent %s')
-                    % nodemod.hex(parent)
+                    % hex(parent)
                 )
             if merge:
                 repo.setparents(p1, parents[1])
@@ -490,7 +486,7 @@
             if line.startswith(b'# Merges'):
                 cur = merges
                 continue
-            cur.append(revlog.bin(line))
+            cur.append(bin(line))
 
         return (nodes, merges)
 
@@ -502,17 +498,17 @@
             os.mkdir(self.path)
         series = self.opener(b'series', b'w')
         for rev in sorted(revmap):
-            series.write(nodemod.hex(revmap[rev]) + b'\n')
+            series.write(hex(revmap[rev]) + b'\n')
         if merges:
             series.write(b'# Merges\n')
             for m in merges:
-                series.write(nodemod.hex(m) + b'\n')
+                series.write(hex(m) + b'\n')
         series.close()
 
     def parselog(self, fp):
         parents = []
         message = []
-        node = revlog.nullid
+        node = self.repo.nullid
         inmsg = False
         user = None
         date = None
@@ -524,9 +520,9 @@
             elif line.startswith(b'# Date '):
                 date = line[7:]
             elif line.startswith(b'# Node ID '):
-                node = revlog.bin(line[10:])
+                node = bin(line[10:])
             elif line.startswith(b'# Parent '):
-                parents.append(revlog.bin(line[9:]))
+                parents.append(bin(line[9:]))
             elif not line.startswith(b'# '):
                 inmsg = True
                 message.append(line)
@@ -544,10 +540,10 @@
         fp = self.opener(b'journal', b'w')
         fp.write(b'# User %s\n' % user)
         fp.write(b'# Date %s\n' % date)
-        fp.write(b'# Node ID %s\n' % nodemod.hex(p2))
-        fp.write(b'# Parent ' + nodemod.hex(p1) + b'\n')
+        fp.write(b'# Node ID %s\n' % hex(p2))
+        fp.write(b'# Parent ' + hex(p1) + b'\n')
         if merge:
-            fp.write(b'# Parent ' + nodemod.hex(p2) + b'\n')
+            fp.write(b'# Parent ' + hex(p2) + b'\n')
         fp.write(message.rstrip() + b'\n')
         fp.close()
 
@@ -564,7 +560,7 @@
         def matchfn(node):
             if self.applied(repo, node, root):
                 return False
-            if source.changelog.parents(node)[1] != revlog.nullid:
+            if source.changelog.parents(node)[1] != repo.nullid:
                 return False
             extra = source.changelog.read(node)[5]
             cnode = extra.get(b'transplant_source')
@@ -800,7 +796,7 @@
     tp = transplanter(ui, repo, opts)
 
     p1 = repo.dirstate.p1()
-    if len(repo) > 0 and p1 == revlog.nullid:
+    if len(repo) > 0 and p1 == repo.nullid:
         raise error.Abort(_(b'no revision checked out'))
     if opts.get(b'continue'):
         if not tp.canresume():
@@ -906,7 +902,7 @@
     changeset if any."""
     ctx = context.resource(mapping, b'ctx')
     n = ctx.extra().get(b'transplant_source')
-    return n and nodemod.hex(n) or b''
+    return n and hex(n) or b''
 
 
 def extsetup(ui):
diff --git a/hgext/uncommit.py b/hgext/uncommit.py
--- a/hgext/uncommit.py
+++ b/hgext/uncommit.py
@@ -27,7 +27,6 @@
     context,
     copies as copiesmod,
     error,
-    node,
     obsutil,
     pathutil,
     pycompat,
@@ -109,7 +108,7 @@
 
     new = context.memctx(
         repo,
-        parents=[base.node(), node.nullid],
+        parents=[base.node(), repo.nullid],
         text=message,
         files=files,
         filectxfn=filectxfn,
diff --git a/mercurial/bookmarks.py b/mercurial/bookmarks.py
--- a/mercurial/bookmarks.py
+++ b/mercurial/bookmarks.py
@@ -15,7 +15,6 @@
     bin,
     hex,
     short,
-    wdirid,
 )
 from .pycompat import getattr
 from . import (
@@ -624,7 +623,7 @@
 _binaryentry = struct.Struct(b'>20sH')
 
 
-def binaryencode(bookmarks):
+def binaryencode(repo, bookmarks):
     """encode a '(bookmark, node)' iterable into a binary stream
 
     the binary format is:
@@ -640,13 +639,13 @@
     binarydata = []
     for book, node in bookmarks:
         if not node:  # None or ''
-            node = wdirid
+            node = repo.nodeconstants.wdirid
         binarydata.append(_binaryentry.pack(node, len(book)))
         binarydata.append(book)
     return b''.join(binarydata)
 
 
-def binarydecode(stream):
+def binarydecode(repo, stream):
     """decode a binary stream into an '(bookmark, node)' iterable
 
     the binary format is:
@@ -672,7 +671,7 @@
         if len(bookmark) < length:
             if entry:
                 raise error.Abort(_(b'bad bookmark stream'))
-        if node == wdirid:
+        if node == repo.nodeconstants.wdirid:
             node = None
         books.append((bookmark, node))
     return books
diff --git a/mercurial/branchmap.py b/mercurial/branchmap.py
--- a/mercurial/branchmap.py
+++ b/mercurial/branchmap.py
@@ -12,7 +12,6 @@
 from .node import (
     bin,
     hex,
-    nullid,
     nullrev,
 )
 from . import (
@@ -87,7 +86,7 @@
                 revs.extend(r for r in extrarevs if r <= bcache.tiprev)
             else:
                 # nothing to fall back on, start empty.
-                bcache = branchcache()
+                bcache = branchcache(repo)
 
         revs.extend(cl.revs(start=bcache.tiprev + 1))
         if revs:
@@ -119,6 +118,7 @@
         if rbheads:
             rtiprev = max((int(clrev(node)) for node in rbheads))
             cache = branchcache(
+                repo,
                 remotebranchmap,
                 repo[rtiprev].node(),
                 rtiprev,
@@ -175,8 +175,9 @@
 
     def __init__(
         self,
+        repo,
         entries=(),
-        tipnode=nullid,
+        tipnode=None,
         tiprev=nullrev,
         filteredhash=None,
         closednodes=None,
@@ -186,7 +187,11 @@
         """ hasnode is a function which can be used to verify whether changelog
         has a given node or not. If it's not provided, we assume that every node
         we have exists in changelog """
-        self.tipnode = tipnode
+        self._repo = repo
+        if tipnode is None:
+            self.tipnode = repo.nullid
+        else:
+            self.tipnode = tipnode
         self.tiprev = tiprev
         self.filteredhash = filteredhash
         # closednodes is a set of nodes that close their branch. If the branch
@@ -271,6 +276,7 @@
             if len(cachekey) > 2:
                 filteredhash = bin(cachekey[2])
             bcache = cls(
+                repo,
                 tipnode=last,
                 tiprev=lrev,
                 filteredhash=filteredhash,
@@ -379,6 +385,7 @@
     def copy(self):
         """return an deep copy of the branchcache object"""
         return type(self)(
+            self._repo,
             self._entries,
             self.tipnode,
             self.tiprev,
@@ -473,7 +480,7 @@
 
         if not self.validfor(repo):
             # cache key are not valid anymore
-            self.tipnode = nullid
+            self.tipnode = repo.nullid
             self.tiprev = nullrev
             for heads in self.iterheads():
                 tiprev = max(cl.rev(node) for node in heads)
diff --git a/mercurial/bundle2.py b/mercurial/bundle2.py
--- a/mercurial/bundle2.py
+++ b/mercurial/bundle2.py
@@ -156,12 +156,15 @@
 import sys
 
 from .i18n import _
+from .node import (
+    hex,
+    short,
+)
 from . import (
     bookmarks,
     changegroup,
     encoding,
     error,
-    node as nodemod,
     obsolete,
     phases,
     pushkey,
@@ -2109,7 +2112,7 @@
     contains binary encoded (bookmark, node) tuple. If the local state does
     not marks the one in the part, a PushRaced exception is raised
     """
-    bookdata = bookmarks.binarydecode(inpart)
+    bookdata = bookmarks.binarydecode(op.repo, inpart)
 
     msgstandard = (
         b'remote repository changed while pushing - please try again '
@@ -2127,14 +2130,14 @@
         currentnode = op.repo._bookmarks.get(book)
         if currentnode != node:
             if node is None:
-                finalmsg = msgexist % (book, nodemod.short(currentnode))
+                finalmsg = msgexist % (book, short(currentnode))
             elif currentnode is None:
-                finalmsg = msgmissing % (book, nodemod.short(node))
+                finalmsg = msgmissing % (book, short(node))
             else:
                 finalmsg = msgstandard % (
                     book,
-                    nodemod.short(node),
-                    nodemod.short(currentnode),
+                    short(node),
+                    short(currentnode),
                 )
             raise error.PushRaced(finalmsg)
 
@@ -2211,7 +2214,7 @@
             actualphase = phasecache.phase(unfi, cl.rev(n))
             if actualphase != expectedphase:
                 finalmsg = msg % (
-                    nodemod.short(n),
+                    short(n),
                     phases.phasenames[actualphase],
                     phases.phasenames[expectedphase],
                 )
@@ -2339,7 +2342,7 @@
     When mode is 'records', the information is recorded into the 'bookmarks'
     records of the bundle operation. This behavior is suitable for pulling.
     """
-    changes = bookmarks.binarydecode(inpart)
+    changes = bookmarks.binarydecode(op.repo, inpart)
 
     pushkeycompat = op.repo.ui.configbool(
         b'server', b'bookmarks-pushkey-compat'
@@ -2356,10 +2359,8 @@
                 hookargs[b'pushkeycompat'] = b'1'
                 hookargs[b'namespace'] = b'bookmarks'
                 hookargs[b'key'] = book
-                hookargs[b'old'] = nodemod.hex(bookstore.get(book, b''))
-                hookargs[b'new'] = nodemod.hex(
-                    node if node is not None else b''
-                )
+                hookargs[b'old'] = hex(bookstore.get(book, b''))
+                hookargs[b'new'] = hex(node if node is not None else b'')
                 allhooks.append(hookargs)
 
             for hookargs in allhooks:
@@ -2565,7 +2566,7 @@
             fullnodes=commonnodes,
         )
         cgdata = packer.generate(
-            {nodemod.nullid},
+            {repo.nullid},
             list(commonnodes),
             False,
             b'narrow_widen',
diff --git a/mercurial/bundlerepo.py b/mercurial/bundlerepo.py
--- a/mercurial/bundlerepo.py
+++ b/mercurial/bundlerepo.py
@@ -17,7 +17,7 @@
 import shutil
 
 from .i18n import _
-from .node import nullid, nullrev
+from .node import nullrev
 
 from . import (
     bundle2,
@@ -172,9 +172,15 @@
 
 class bundlemanifest(bundlerevlog, manifest.manifestrevlog):
     def __init__(
-        self, opener, cgunpacker, linkmapper, dirlogstarts=None, dir=b''
+        self,
+        nodeconstants,
+        opener,
+        cgunpacker,
+        linkmapper,
+        dirlogstarts=None,
+        dir=b'',
     ):
-        manifest.manifestrevlog.__init__(self, opener, tree=dir)
+        manifest.manifestrevlog.__init__(self, nodeconstants, opener, tree=dir)
         bundlerevlog.__init__(
             self, opener, self.indexfile, cgunpacker, linkmapper
         )
@@ -189,6 +195,7 @@
         if d in self._dirlogstarts:
             self.bundle.seek(self._dirlogstarts[d])
             return bundlemanifest(
+                self.nodeconstants,
                 self.opener,
                 self.bundle,
                 self._linkmapper,
@@ -366,7 +373,9 @@
         # consume the header if it exists
         self._cgunpacker.manifestheader()
         linkmapper = self.unfiltered().changelog.rev
-        rootstore = bundlemanifest(self.svfs, self._cgunpacker, linkmapper)
+        rootstore = bundlemanifest(
+            self.nodeconstants, self.svfs, self._cgunpacker, linkmapper
+        )
         self.filestart = self._cgunpacker.tell()
 
         return manifest.manifestlog(
@@ -433,7 +442,9 @@
         return encoding.getcwd()  # always outside the repo
 
     # Check if parents exist in localrepo before setting
-    def setparents(self, p1, p2=nullid):
+    def setparents(self, p1, p2=None):
+        if p2 is None:
+            p2 = self.nullid
         p1rev = self.changelog.rev(p1)
         p2rev = self.changelog.rev(p2)
         msg = _(b"setting parent to node %s that only exists in the bundle\n")
diff --git a/mercurial/changegroup.py b/mercurial/changegroup.py
--- a/mercurial/changegroup.py
+++ b/mercurial/changegroup.py
@@ -14,7 +14,6 @@
 from .i18n import _
 from .node import (
     hex,
-    nullid,
     nullrev,
     short,
 )
@@ -559,7 +558,7 @@
         return readexactly(self._fh, n)
 
 
-def _revisiondeltatochunks(delta, headerfn):
+def _revisiondeltatochunks(repo, delta, headerfn):
     """Serialize a revisiondelta to changegroup chunks."""
 
     # The captured revision delta may be encoded as a delta against
@@ -570,7 +569,7 @@
 
     if delta.delta is not None:
         prefix, data = b'', delta.delta
-    elif delta.basenode == nullid:
+    elif delta.basenode == repo.nullid:
         data = delta.revision
         prefix = mdiff.trivialdiffheader(len(data))
     else:
@@ -932,7 +931,9 @@
             cl, clnodes, generate=changelog
         )
         for delta in deltas:
-            for chunk in _revisiondeltatochunks(delta, self._builddeltaheader):
+            for chunk in _revisiondeltatochunks(
+                self._repo, delta, self._builddeltaheader
+            ):
                 size += len(chunk)
                 yield chunk
 
@@ -987,7 +988,9 @@
                 yield chunk
 
             for delta in deltas:
-                chunks = _revisiondeltatochunks(delta, self._builddeltaheader)
+                chunks = _revisiondeltatochunks(
+                    self._repo, delta, self._builddeltaheader
+                )
                 for chunk in chunks:
                     size += len(chunk)
                     yield chunk
@@ -1025,7 +1028,9 @@
             yield h
 
             for delta in deltas:
-                chunks = _revisiondeltatochunks(delta, self._builddeltaheader)
+                chunks = _revisiondeltatochunks(
+                    self._repo, delta, self._builddeltaheader
+                )
                 for chunk in chunks:
                     size += len(chunk)
                     yield chunk
diff --git a/mercurial/changelog.py b/mercurial/changelog.py
--- a/mercurial/changelog.py
+++ b/mercurial/changelog.py
@@ -11,7 +11,6 @@
 from .node import (
     bin,
     hex,
-    nullid,
 )
 from .thirdparty import attr
 
@@ -191,7 +190,7 @@
     # Extensions might modify _defaultextra, so let the constructor below pass
     # it in
     extra = attr.ib()
-    manifest = attr.ib(default=nullid)
+    manifest = attr.ib()
     user = attr.ib(default=b'')
     date = attr.ib(default=(0, 0))
     files = attr.ib(default=attr.Factory(list))
@@ -218,9 +217,9 @@
         '_changes',
     )
 
-    def __new__(cls, text, sidedata, cpsd):
+    def __new__(cls, cl, text, sidedata, cpsd):
         if not text:
-            return _changelogrevision(extra=_defaultextra)
+            return _changelogrevision(extra=_defaultextra, manifest=cl.nullid)
 
         self = super(changelogrevision, cls).__new__(cls)
         # We could return here and implement the following as an __init__.
@@ -515,7 +514,7 @@
         """
         d, s = self._revisiondata(node)
         c = changelogrevision(
-            d, s, self._copiesstorage == b'changeset-sidedata'
+            self, d, s, self._copiesstorage == b'changeset-sidedata'
         )
         return (c.manifest, c.user, c.date, c.files, c.description, c.extra)
 
@@ -523,7 +522,7 @@
         """Obtain a ``changelogrevision`` for a node or revision."""
         text, sidedata = self._revisiondata(nodeorrev)
         return changelogrevision(
-            text, sidedata, self._copiesstorage == b'changeset-sidedata'
+            self, text, sidedata, self._copiesstorage == b'changeset-sidedata'
         )
 
     def readfiles(self, node):
diff --git a/mercurial/chgserver.py b/mercurial/chgserver.py
--- a/mercurial/chgserver.py
+++ b/mercurial/chgserver.py
@@ -54,13 +54,13 @@
     getattr,
     setattr,
 )
+from .node import hex
 
 from . import (
     commandserver,
     encoding,
     error,
     extensions,
-    node,
     pycompat,
     util,
 )
@@ -74,7 +74,7 @@
 
 def _hashlist(items):
     """return sha1 hexdigest for a list"""
-    return node.hex(hashutil.sha1(stringutil.pprint(items)).digest())
+    return hex(hashutil.sha1(stringutil.pprint(items)).digest())
 
 
 # sensitive config sections affecting confighash
diff --git a/mercurial/cmdutil.py b/mercurial/cmdutil.py
--- a/mercurial/cmdutil.py
+++ b/mercurial/cmdutil.py
@@ -15,7 +15,7 @@
 from .i18n import _
 from .node import (
     hex,
-    nullid,
+    nullrev,
     short,
 )
 from .pycompat import (
@@ -1086,7 +1086,7 @@
     'hint' is the usual hint given to Abort exception.
     """
 
-    if merge and repo.dirstate.p2() != nullid:
+    if merge and repo.dirstate.p2() != repo.nullid:
         raise error.StateError(_(b'outstanding uncommitted merge'), hint=hint)
     st = repo.status()
     if st.modified or st.added or st.removed or st.deleted:
@@ -1926,12 +1926,12 @@
     ui.debug(b'message:\n%s\n' % (message or b''))
 
     if len(parents) == 1:
-        parents.append(repo[nullid])
+        parents.append(repo[nullrev])
     if opts.get(b'exact'):
         if not nodeid or not p1:
             raise error.InputError(_(b'not a Mercurial patch'))
         p1 = repo[p1]
-        p2 = repo[p2 or nullid]
+        p2 = repo[p2 or nullrev]
     elif p2:
         try:
             p1 = repo[p1]
@@ -1941,10 +1941,10 @@
             # first parent.
             if p1 != parents[0]:
                 p1 = parents[0]
-                p2 = repo[nullid]
+                p2 = repo[nullrev]
         except error.RepoError:
             p1, p2 = parents
-        if p2.node() == nullid:
+        if p2.node() == repo.nullid:
             ui.warn(
                 _(
                     b"warning: import the patch as a normal revision\n"
@@ -2093,7 +2093,7 @@
     if parents:
         prev = parents[0]
     else:
-        prev = nullid
+        prev = repo.nullid
 
     fm.context(ctx=ctx)
     fm.plain(b'# HG changeset patch\n')
@@ -2956,7 +2956,7 @@
         ms.reset()
 
         # Reroute the working copy parent to the new changeset
-        repo.setparents(newid, nullid)
+        repo.setparents(newid, repo.nullid)
         mapping = {old.node(): (newid,)}
         obsmetadata = None
         if opts.get(b'note'):
@@ -3310,7 +3310,7 @@
 
         # in case of merge, files that are actually added can be reported as
         # modified, we need to post process the result
-        if p2 != nullid:
+        if p2 != repo.nullid:
             mergeadd = set(dsmodified)
             for path in dsmodified:
                 if path in mf:
@@ -3580,7 +3580,7 @@
         # We're reverting to our parent. If possible, we'd like status
         # to report the file as clean. We have to use normallookup for
         # merges to avoid losing information about merged/dirty files.
-        if p2 != nullid:
+        if p2 != repo.nullid:
             normal = repo.dirstate.normallookup
         else:
             normal = repo.dirstate.normal
@@ -3677,7 +3677,7 @@
             repo.dirstate.add(f)
 
     normal = repo.dirstate.normallookup
-    if node == parent and p2 == nullid:
+    if node == parent and p2 == repo.nullid:
         normal = repo.dirstate.normal
     for f in actions[b'undelete'][0]:
         if interactive:
diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -15,10 +15,8 @@
 from .i18n import _
 from .node import (
     hex,
-    nullid,
     nullrev,
     short,
-    wdirhex,
     wdirrev,
 )
 from .pycompat import open
@@ -479,7 +477,7 @@
                     return b'%d ' % rev
 
         def formathex(h):
-            if h == wdirhex:
+            if h == repo.nodeconstants.wdirhex:
                 return b'%s+' % shorthex(hex(ctx.p1().node()))
             else:
                 return b'%s ' % shorthex(h)
@@ -802,9 +800,9 @@
         )
 
     p1, p2 = repo.changelog.parents(node)
-    if p1 == nullid:
+    if p1 == repo.nullid:
         raise error.InputError(_(b'cannot backout a change with no parents'))
-    if p2 != nullid:
+    if p2 != repo.nullid:
         if not opts.get(b'parent'):
             raise error.InputError(_(b'cannot backout a merge changeset'))
         p = repo.lookup(opts[b'parent'])
@@ -1073,7 +1071,7 @@
                 )
         else:
             node, p2 = repo.dirstate.parents()
-            if p2 != nullid:
+            if p2 != repo.nullid:
                 raise error.StateError(_(b'current bisect revision is a merge'))
         if rev:
             node = repo[scmutil.revsingle(repo, rev, node)].node()
@@ -4773,7 +4771,7 @@
 
     opts = pycompat.byteskwargs(opts)
     abort = opts.get(b'abort')
-    if abort and repo.dirstate.p2() == nullid:
+    if abort and repo.dirstate.p2() == repo.nullid:
         cmdutil.wrongtooltocontinue(repo, _(b'merge'))
     cmdutil.check_incompatible_arguments(opts, b'abort', [b'rev', b'preview'])
     if abort:
@@ -5021,7 +5019,7 @@
 
     displayer = logcmdutil.changesetdisplayer(ui, repo, opts)
     for n in p:
-        if n != nullid:
+        if n != repo.nullid:
             displayer.show(repo[n])
     displayer.close()
 
@@ -5904,7 +5902,7 @@
     with repo.wlock():
         ms = mergestatemod.mergestate.read(repo)
 
-        if not (ms.active() or repo.dirstate.p2() != nullid):
+        if not (ms.active() or repo.dirstate.p2() != repo.nullid):
             raise error.StateError(
                 _(b'resolve command not applicable when not merging')
             )
@@ -6022,7 +6020,7 @@
                     raise
 
         ms.commit()
-        branchmerge = repo.dirstate.p2() != nullid
+        branchmerge = repo.dirstate.p2() != repo.nullid
         mergestatemod.recordupdates(repo, ms.actions(), branchmerge, None)
 
         if not didwork and pats:
@@ -6114,7 +6112,7 @@
         opts[b"rev"] = cmdutil.finddate(ui, repo, opts[b"date"])
 
     parent, p2 = repo.dirstate.parents()
-    if not opts.get(b'rev') and p2 != nullid:
+    if not opts.get(b'rev') and p2 != repo.nullid:
         # revert after merge is a trap for new users (issue2915)
         raise error.InputError(
             _(b'uncommitted merge with no revision specified'),
@@ -6134,7 +6132,7 @@
         or opts.get(b'interactive')
     ):
         msg = _(b"no files or directories specified")
-        if p2 != nullid:
+        if p2 != repo.nullid:
             hint = _(
                 b"uncommitted merge, use --all to discard all changes,"
                 b" or 'hg update -C .' to abort the merge"
@@ -7169,7 +7167,7 @@
             for n in names:
                 if repo.tagtype(n) == b'global':
                     alltags = tagsmod.findglobaltags(ui, repo)
-                    if alltags[n][0] == nullid:
+                    if alltags[n][0] == repo.nullid:
                         raise error.InputError(
                             _(b"tag '%s' is already removed") % n
                         )
@@ -7196,7 +7194,7 @@
                     )
         if not opts.get(b'local'):
             p1, p2 = repo.dirstate.parents()
-            if p2 != nullid:
+            if p2 != repo.nullid:
                 raise error.StateError(_(b'uncommitted merge'))
             bheads = repo.branchheads()
             if not opts.get(b'force') and bheads and p1 not in bheads:
diff --git a/mercurial/commit.py b/mercurial/commit.py
--- a/mercurial/commit.py
+++ b/mercurial/commit.py
@@ -10,7 +10,6 @@
 from .i18n import _
 from .node import (
     hex,
-    nullid,
     nullrev,
 )
 
@@ -262,10 +261,10 @@
     """
 
     fname = fctx.path()
-    fparent1 = manifest1.get(fname, nullid)
-    fparent2 = manifest2.get(fname, nullid)
+    fparent1 = manifest1.get(fname, repo.nullid)
+    fparent2 = manifest2.get(fname, repo.nullid)
     touched = None
-    if fparent1 == fparent2 == nullid:
+    if fparent1 == fparent2 == repo.nullid:
         touched = 'added'
 
     if isinstance(fctx, context.filectx):
@@ -276,9 +275,11 @@
         if node in [fparent1, fparent2]:
             repo.ui.debug(b'reusing %s filelog entry\n' % fname)
             if (
-                fparent1 != nullid and manifest1.flags(fname) != fctx.flags()
+                fparent1 != repo.nullid
+                and manifest1.flags(fname) != fctx.flags()
             ) or (
-                fparent2 != nullid and manifest2.flags(fname) != fctx.flags()
+                fparent2 != repo.nullid
+                and manifest2.flags(fname) != fctx.flags()
             ):
                 touched = 'modified'
             return node, touched
@@ -312,7 +313,9 @@
         newfparent = fparent2
 
         if manifest2:  # branch merge
-            if fparent2 == nullid or cnode is None:  # copied on remote side
+            if (
+                fparent2 == repo.nullid or cnode is None
+            ):  # copied on remote side
                 if cfname in manifest2:
                     cnode = manifest2[cfname]
                     newfparent = fparent1
@@ -331,7 +334,7 @@
             if includecopymeta:
                 meta[b"copy"] = cfname
                 meta[b"copyrev"] = hex(cnode)
-            fparent1, fparent2 = nullid, newfparent
+            fparent1, fparent2 = repo.nullid, newfparent
         else:
             repo.ui.warn(
                 _(
@@ -341,22 +344,22 @@
                 % (fname, cfname)
             )
 
-    elif fparent1 == nullid:
-        fparent1, fparent2 = fparent2, nullid
-    elif fparent2 != nullid:
+    elif fparent1 == repo.nullid:
+        fparent1, fparent2 = fparent2, repo.nullid
+    elif fparent2 != repo.nullid:
         # is one parent an ancestor of the other?
         fparentancestors = flog.commonancestorsheads(fparent1, fparent2)
         if fparent1 in fparentancestors:
-            fparent1, fparent2 = fparent2, nullid
+            fparent1, fparent2 = fparent2, repo.nullid
         elif fparent2 in fparentancestors:
-            fparent2 = nullid
+            fparent2 = repo.nullid
         elif not fparentancestors:
             # TODO: this whole if-else might be simplified much more
             if (
                 ms.active()
                 and ms.extras(fname).get(b'filenode-source') == b'other'
             ):
-                fparent1, fparent2 = fparent2, nullid
+                fparent1, fparent2 = fparent2, repo.nullid
 
     force_new_node = False
     # The file might have been deleted by merge code and user explicitly choose
@@ -371,9 +374,14 @@
         force_new_node = True
     # is the file changed?
     text = fctx.data()
-    if fparent2 != nullid or meta or flog.cmp(fparent1, text) or force_new_node:
+    if (
+        fparent2 != repo.nullid
+        or meta
+        or flog.cmp(fparent1, text)
+        or force_new_node
+    ):
         if touched is None:  # do not overwrite added
-            if fparent2 == nullid:
+            if fparent2 == repo.nullid:
                 touched = 'modified'
             else:
                 touched = 'merged'
diff --git a/mercurial/context.py b/mercurial/context.py
--- a/mercurial/context.py
+++ b/mercurial/context.py
@@ -14,14 +14,9 @@
 
 from .i18n import _
 from .node import (
-    addednodeid,
     hex,
-    modifiednodeid,
-    nullid,
     nullrev,
     short,
-    wdirfilenodeids,
-    wdirhex,
 )
 from .pycompat import (
     getattr,
@@ -140,7 +135,7 @@
                 removed.append(fn)
             elif flag1 != flag2:
                 modified.append(fn)
-            elif node2 not in wdirfilenodeids:
+            elif node2 not in self._repo.nodeconstants.wdirfilenodeids:
                 # When comparing files between two commits, we save time by
                 # not comparing the file contents when the nodeids differ.
                 # Note that this means we incorrectly report a reverted change
@@ -737,7 +732,7 @@
             n2 = c2._parents[0]._node
         cahs = self._repo.changelog.commonancestorsheads(self._node, n2)
         if not cahs:
-            anc = nullid
+            anc = self._repo.nodeconstants.nullid
         elif len(cahs) == 1:
             anc = cahs[0]
         else:
@@ -1131,7 +1126,11 @@
         _path = self._path
         fl = self._filelog
         parents = self._filelog.parents(self._filenode)
-        pl = [(_path, node, fl) for node in parents if node != nullid]
+        pl = [
+            (_path, node, fl)
+            for node in parents
+            if node != self._repo.nodeconstants.nullid
+        ]
 
         r = fl.renamed(self._filenode)
         if r:
@@ -1554,12 +1553,12 @@
         return self._repo.dirstate[key] not in b"?r"
 
     def hex(self):
-        return wdirhex
+        return self._repo.nodeconstants.wdirhex
 
     @propertycache
     def _parents(self):
         p = self._repo.dirstate.parents()
-        if p[1] == nullid:
+        if p[1] == self._repo.nodeconstants.nullid:
             p = p[:-1]
         # use unfiltered repo to delay/avoid loading obsmarkers
         unfi = self._repo.unfiltered()
@@ -1570,7 +1569,9 @@
             for n in p
         ]
 
-    def setparents(self, p1node, p2node=nullid):
+    def setparents(self, p1node, p2node=None):
+        if p2node is None:
+            p2node = self._repo.nodeconstants.nullid
         dirstate = self._repo.dirstate
         with dirstate.parentchange():
             copies = dirstate.setparents(p1node, p2node)
@@ -1582,7 +1583,7 @@
                 for f in copies:
                     if f not in pctx and copies[f] in pctx:
                         dirstate.copy(copies[f], f)
-            if p2node == nullid:
+            if p2node == self._repo.nodeconstants.nullid:
                 for f, s in sorted(dirstate.copies().items()):
                     if f not in pctx and s not in pctx:
                         dirstate.copy(None, f)
@@ -1942,8 +1943,8 @@
 
         ff = self._flagfunc
         for i, l in (
-            (addednodeid, status.added),
-            (modifiednodeid, status.modified),
+            (self._repo.nodeconstants.addednodeid, status.added),
+            (self._repo.nodeconstants.modifiednodeid, status.modified),
         ):
             for f in l:
                 man[f] = i
@@ -2068,13 +2069,18 @@
         path = self.copysource()
         if not path:
             return None
-        return path, self._changectx._parents[0]._manifest.get(path, nullid)
+        return (
+            path,
+            self._changectx._parents[0]._manifest.get(
+                path, self._repo.nodeconstants.nullid
+            ),
+        )
 
     def parents(self):
         '''return parent filectxs, following copies if necessary'''
 
         def filenode(ctx, path):
-            return ctx._manifest.get(path, nullid)
+            return ctx._manifest.get(path, self._repo.nodeconstants.nullid)
 
         path = self._path
         fl = self._filelog
@@ -2092,7 +2098,7 @@
         return [
             self._parentfilectx(p, fileid=n, filelog=l)
             for p, n, l in pl
-            if n != nullid
+            if n != self._repo.nodeconstants.nullid
         ]
 
     def children(self):
@@ -2220,7 +2226,9 @@
         # ``overlayworkingctx`` (e.g. with --collapse).
         util.clearcachedproperty(self, b'_manifest')
 
-    def setparents(self, p1node, p2node=nullid):
+    def setparents(self, p1node, p2node=None):
+        if p2node is None:
+            p2node = self._repo.nodeconstants.nullid
         assert p1node == self._wrappedctx.node()
         self._parents = [self._wrappedctx, self._repo.unfiltered()[p2node]]
 
@@ -2246,10 +2254,10 @@
 
         flag = self._flagfunc
         for path in self.added():
-            man[path] = addednodeid
+            man[path] = self._repo.nodeconstants.addednodeid
             man.setflag(path, flag(path))
         for path in self.modified():
-            man[path] = modifiednodeid
+            man[path] = self._repo.nodeconstants.modifiednodeid
             man.setflag(path, flag(path))
         for path in self.removed():
             del man[path]
@@ -2825,7 +2833,7 @@
         )
         self._rev = None
         self._node = None
-        parents = [(p or nullid) for p in parents]
+        parents = [(p or self._repo.nodeconstants.nullid) for p in parents]
         p1, p2 = parents
         self._parents = [self._repo[p] for p in (p1, p2)]
         files = sorted(set(files))
@@ -2864,10 +2872,10 @@
         man = pctx.manifest().copy()
 
         for f in self._status.modified:
-            man[f] = modifiednodeid
+            man[f] = self._repo.nodeconstants.modifiednodeid
 
         for f in self._status.added:
-            man[f] = addednodeid
+            man[f] = self._repo.nodeconstants.addednodeid
 
         for f in self._status.removed:
             if f in man:
@@ -2884,7 +2892,7 @@
         # "1 < len(self._parents)" can't be used for checking
         # existence of the 2nd parent, because "memctx._parents" is
         # explicitly initialized by the list, of which length is 2.
-        if p2.node() != nullid:
+        if p2.node() != self._repo.nodeconstants.nullid:
             man2 = p2.manifest()
             managing = lambda f: f in man1 or f in man2
         else:
@@ -2902,7 +2910,7 @@
         return scmutil.status(modified, added, removed, [], [], [], [])
 
     def parents(self):
-        if self._parents[1].node() == nullid:
+        if self._parents[1].rev() == nullrev:
             return [self._parents[0]]
         return self._parents
 
@@ -2999,18 +3007,18 @@
             parents = [repo[p] for p in parents if p is not None]
         parents = parents[:]
         while len(parents) < 2:
-            parents.append(repo[nullid])
+            parents.append(repo[nullrev])
         p1, p2 = self._parents = parents
 
         # sanity check to ensure that the reused manifest parents are
         # manifests of our commit parents
         mp1, mp2 = self.manifestctx().parents
-        if p1 != nullid and p1.manifestnode() != mp1:
+        if p1 != self._repo.nodeconstants.nullid and p1.manifestnode() != mp1:
             raise RuntimeError(
                 r"can't reuse the manifest: its p1 "
                 r"doesn't match the new ctx p1"
             )
-        if p2 != nullid and p2.manifestnode() != mp2:
+        if p2 != self._repo.nodeconstants.nullid and p2.manifestnode() != mp2:
             raise RuntimeError(
                 r"can't reuse the manifest: "
                 r"its p2 doesn't match the new ctx p2"
@@ -3051,7 +3059,7 @@
         # "1 < len(self._parents)" can't be used for checking
         # existence of the 2nd parent, because "metadataonlyctx._parents" is
         # explicitly initialized by the list, of which length is 2.
-        if p2.node() != nullid:
+        if p2.rev() != nullrev:
             man2 = p2.manifest()
             managing = lambda f: f in man1 or f in man2
         else:
diff --git a/mercurial/copies.py b/mercurial/copies.py
--- a/mercurial/copies.py
+++ b/mercurial/copies.py
@@ -11,11 +11,11 @@
 import os
 
 from .i18n import _
+from .node import nullrev
 
 
 from . import (
     match as matchmod,
-    node,
     pathutil,
     pycompat,
     util,
@@ -141,7 +141,7 @@
     # optimization, since the ctx.files() for a merge commit is not correct for
     # this comparison.
     forwardmissingmatch = match
-    if b.p1() == a and b.p2().node() == node.nullid:
+    if b.p1() == a and b.p2().node() == repo.nullid:
         filesmatcher = matchmod.exact(b.files())
         forwardmissingmatch = matchmod.intersectmatchers(match, filesmatcher)
     missing = _computeforwardmissing(a, b, match=forwardmissingmatch)
@@ -222,7 +222,7 @@
         if flags(rev) & HASCOPIESINFO:
             changes = changelogrevision(rev).changes
         value = (p1, p2, changes)
-        if p1 != node.nullrev and p2 != node.nullrev:
+        if p1 != nullrev and p2 != nullrev:
             # XXX some case we over cache, IGNORE
             merge_caches[rev] = value
         return value
@@ -249,7 +249,7 @@
 
 
 def _changesetforwardcopies(a, b, match):
-    if a.rev() in (node.nullrev, b.rev()):
+    if a.rev() in (nullrev, b.rev()):
         return {}
 
     repo = a.repo().unfiltered()
@@ -262,7 +262,7 @@
     roots = set()
     for r in missingrevs:
         for p in cl.parentrevs(r):
-            if p == node.nullrev:
+            if p == nullrev:
                 continue
             if p not in children:
                 children[p] = [r]
@@ -447,7 +447,7 @@
             parents = fctx._filelog.parents(fctx._filenode)
             nb_parents = 0
             for n in parents:
-                if n != node.nullid:
+                if n != repo.nullid:
                     nb_parents += 1
             return nb_parents >= 2
 
@@ -621,7 +621,7 @@
         if debug:
             repo.ui.debug(b'debug.copies: search mode: combined\n')
         base = None
-        if a.rev() != node.nullrev:
+        if a.rev() != nullrev:
             base = x
         copies = _chain(
             _backwardrenames(x, a, match=match),
diff --git a/mercurial/debugcommands.py b/mercurial/debugcommands.py
--- a/mercurial/debugcommands.py
+++ b/mercurial/debugcommands.py
@@ -29,7 +29,6 @@
 from .node import (
     bin,
     hex,
-    nullid,
     nullrev,
     short,
 )
@@ -1492,7 +1491,7 @@
         node = r.node(i)
         pp = r.parents(node)
         ui.write(b"\t%d -> %d\n" % (r.rev(pp[0]), i))
-        if pp[1] != nullid:
+        if pp[1] != repo.nullid:
             ui.write(b"\t%d -> %d\n" % (r.rev(pp[1]), i))
     ui.write(b"}\n")
 
@@ -1500,7 +1499,7 @@
 @command(b'debugindexstats', [])
 def debugindexstats(ui, repo):
     """show stats related to the changelog index"""
-    repo.changelog.shortest(nullid, 1)
+    repo.changelog.shortest(repo.nullid, 1)
     index = repo.changelog.index
     if not util.safehasattr(index, b'stats'):
         raise error.Abort(_(b'debugindexstats only works with native code'))
@@ -2249,7 +2248,7 @@
             # arbitrary node identifiers, possibly not present in the
             # local repository.
             n = bin(s)
-            if len(n) != len(nullid):
+            if len(n) != len(repo.nullid):
                 raise TypeError()
             return n
         except TypeError:
@@ -3143,7 +3142,7 @@
             try:
                 pp = r.parents(node)
             except Exception:
-                pp = [nullid, nullid]
+                pp = [repo.nullid, repo.nullid]
             if ui.verbose:
                 ui.write(
                     b"% 6d % 9d % 7d % 7d %s %s %s\n"
@@ -3545,7 +3544,9 @@
         for n in chlist:
             if limit is not None and count >= limit:
                 break
-            parents = [True for p in other.changelog.parents(n) if p != nullid]
+            parents = [
+                True for p in other.changelog.parents(n) if p != repo.nullid
+            ]
             if opts.get(b"no_merges") and len(parents) == 2:
                 continue
             count += 1
diff --git a/mercurial/dirstate.py b/mercurial/dirstate.py
--- a/mercurial/dirstate.py
+++ b/mercurial/dirstate.py
@@ -14,7 +14,6 @@
 import stat
 
 from .i18n import _
-from .node import nullid
 from .pycompat import delattr
 
 from hgdemandimport import tracing
@@ -73,13 +72,16 @@
 
 @interfaceutil.implementer(intdirstate.idirstate)
 class dirstate(object):
-    def __init__(self, opener, ui, root, validate, sparsematchfn):
+    def __init__(
+        self, opener, ui, root, validate, sparsematchfn, nodeconstants
+    ):
         '''Create a new dirstate object.
 
         opener is an open()-like callable that can be used to open the
         dirstate file; root is the root of the directory tracked by
         the dirstate.
         '''
+        self._nodeconstants = nodeconstants
         self._opener = opener
         self._validate = validate
         self._root = root
@@ -136,7 +138,9 @@
     @propertycache
     def _map(self):
         """Return the dirstate contents (see documentation for dirstatemap)."""
-        self._map = self._mapcls(self._ui, self._opener, self._root)
+        self._map = self._mapcls(
+            self._ui, self._opener, self._root, self._nodeconstants
+        )
         return self._map
 
     @property
@@ -309,7 +313,7 @@
     def branch(self):
         return encoding.tolocal(self._branch)
 
-    def setparents(self, p1, p2=nullid):
+    def setparents(self, p1, p2=None):
         """Set dirstate parents to p1 and p2.
 
         When moving from two parents to one, 'm' merged entries a
@@ -318,6 +322,8 @@
 
         See localrepo.setparents()
         """
+        if p2 is None:
+            p2 = self._nodeconstants.nullid
         if self._parentwriters == 0:
             raise ValueError(
                 b"cannot set dirstate parent outside of "
@@ -330,7 +336,10 @@
             self._origpl = self._pl
         self._map.setparents(p1, p2)
         copies = {}
-        if oldp2 != nullid and p2 == nullid:
+        if (
+            oldp2 != self._nodeconstants.nullid
+            and p2 == self._nodeconstants.nullid
+        ):
             candidatefiles = self._map.nonnormalset.union(
                 self._map.otherparentset
             )
@@ -454,7 +463,7 @@
 
     def normallookup(self, f):
         '''Mark a file normal, but possibly dirty.'''
-        if self._pl[1] != nullid:
+        if self._pl[1] != self._nodeconstants.nullid:
             # if there is a merge going on and the file was either
             # in state 'm' (-1) or coming from other parent (-2) before
             # being removed, restore that state.
@@ -476,7 +485,7 @@
 
     def otherparent(self, f):
         '''Mark as coming from the other parent, always dirty.'''
-        if self._pl[1] == nullid:
+        if self._pl[1] == self._nodeconstants.nullid:
             raise error.Abort(
                 _(b"setting %r to other parent only allowed in merges") % f
             )
@@ -498,7 +507,7 @@
         self._dirty = True
         oldstate = self[f]
         size = 0
-        if self._pl[1] != nullid:
+        if self._pl[1] != self._nodeconstants.nullid:
             entry = self._map.get(f)
             if entry is not None:
                 # backup the previous state
@@ -514,7 +523,7 @@
 
     def merge(self, f):
         '''Mark a file merged.'''
-        if self._pl[1] == nullid:
+        if self._pl[1] == self._nodeconstants.nullid:
             return self.normallookup(f)
         return self.otherparent(f)
 
@@ -633,7 +642,7 @@
 
         if self._origpl is None:
             self._origpl = self._pl
-        self._map.setparents(parent, nullid)
+        self._map.setparents(parent, self._nodeconstants.nullid)
 
         for f in to_lookup:
             self.normallookup(f)
@@ -1420,12 +1429,13 @@
       denormalized form that they appear as in the dirstate.
     """
 
-    def __init__(self, ui, opener, root):
+    def __init__(self, ui, opener, root, nodeconstants):
         self._ui = ui
         self._opener = opener
         self._root = root
         self._filename = b'dirstate'
-        self._nodelen = 20
+        self._nodeconstants = nodeconstants
+        self._nodelen = len(nodeconstants.nullid)
 
         self._parents = None
         self._dirtyparents = False
@@ -1448,7 +1458,7 @@
     def clear(self):
         self._map.clear()
         self.copymap.clear()
-        self.setparents(nullid, nullid)
+        self.setparents(self._nodeconstants.nullid, self._nodeconstants.nullid)
         util.clearcachedproperty(self, b"_dirs")
         util.clearcachedproperty(self, b"_alldirs")
         util.clearcachedproperty(self, b"filefoldmap")
@@ -1625,7 +1635,10 @@
                     st[self._nodelen : 2 * self._nodelen],
                 )
             elif l == 0:
-                self._parents = (nullid, nullid)
+                self._parents = (
+                    self._nodeconstants.nullid,
+                    self._nodeconstants.nullid,
+                )
             else:
                 raise error.Abort(
                     _(b'working directory state appears damaged!')
@@ -1724,7 +1737,8 @@
 if rustmod is not None:
 
     class dirstatemap(object):
-        def __init__(self, ui, opener, root):
+        def __init__(self, ui, opener, root, nodeconstants):
+            self._nodeconstants = nodeconstants
             self._ui = ui
             self._opener = opener
             self._root = root
@@ -1782,7 +1796,9 @@
         def clear(self):
             self._rustmap.clear()
             self._inner_rustmap.clear()
-            self.setparents(nullid, nullid)
+            self.setparents(
+                self._nodeconstants.nullid, self._nodeconstants.nullid
+            )
             util.clearcachedproperty(self, b"_dirs")
             util.clearcachedproperty(self, b"_alldirs")
             util.clearcachedproperty(self, b"dirfoldmap")
diff --git a/mercurial/discovery.py b/mercurial/discovery.py
--- a/mercurial/discovery.py
+++ b/mercurial/discovery.py
@@ -12,7 +12,6 @@
 from .i18n import _
 from .node import (
     hex,
-    nullid,
     short,
 )
 
@@ -107,7 +106,7 @@
         if missingroots:
             discbases = []
             for n in missingroots:
-                discbases.extend([p for p in cl.parents(n) if p != nullid])
+                discbases.extend([p for p in cl.parents(n) if p != repo.nullid])
             # TODO remove call to nodesbetween.
             # TODO populate attributes on outgoing instance instead of setting
             # discbases.
@@ -116,7 +115,7 @@
             ancestorsof = heads
             commonheads = [n for n in discbases if n not in included]
         elif not commonheads:
-            commonheads = [nullid]
+            commonheads = [repo.nullid]
         self.commonheads = commonheads
         self.ancestorsof = ancestorsof
         self._revlog = cl
@@ -270,9 +269,12 @@
     # C. Update newmap with outgoing changes.
     # This will possibly add new heads and remove existing ones.
     newmap = branchmap.remotebranchcache(
-        (branch, heads[1])
-        for branch, heads in pycompat.iteritems(headssum)
-        if heads[0] is not None
+        repo,
+        (
+            (branch, heads[1])
+            for branch, heads in pycompat.iteritems(headssum)
+            if heads[0] is not None
+        ),
     )
     newmap.update(repo, (ctx.rev() for ctx in missingctx))
     for branch, newheads in pycompat.iteritems(newmap):
@@ -375,7 +377,7 @@
     # - a local outgoing head descended from update
     # - a remote head that's known locally and not
     #   ancestral to an outgoing head
-    if remoteheads == [nullid]:
+    if remoteheads == [repo.nullid]:
         # remote is empty, nothing to check.
         return
 
diff --git a/mercurial/exchange.py b/mercurial/exchange.py
--- a/mercurial/exchange.py
+++ b/mercurial/exchange.py
@@ -13,7 +13,6 @@
 from .i18n import _
 from .node import (
     hex,
-    nullid,
     nullrev,
 )
 from . import (
@@ -163,7 +162,7 @@
         hasnode = cl.hasnode
         common = [n for n in common if hasnode(n)]
     else:
-        common = [nullid]
+        common = [repo.nullid]
     if not heads:
         heads = cl.heads()
     return discovery.outgoing(repo, common, heads)
@@ -814,7 +813,7 @@
     data = []
     for book, old, new in pushop.outbookmarks:
         data.append((book, old))
-    checkdata = bookmod.binaryencode(data)
+    checkdata = bookmod.binaryencode(pushop.repo, data)
     bundler.newpart(b'check:bookmarks', data=checkdata)
 
 
@@ -1007,7 +1006,7 @@
         _abortonsecretctx(pushop, new, book)
         data.append((book, new))
         allactions.append((book, _bmaction(old, new)))
-    checkdata = bookmod.binaryencode(data)
+    checkdata = bookmod.binaryencode(pushop.repo, data)
     bundler.newpart(b'bookmarks', data=checkdata)
 
     def handlereply(op):
@@ -1801,7 +1800,7 @@
     if (
         pullop.remote.capable(b'clonebundles')
         and pullop.heads is None
-        and list(pullop.common) == [nullid]
+        and list(pullop.common) == [pullop.repo.nullid]
     ):
         kwargs[b'cbattempted'] = pullop.clonebundleattempted
 
@@ -1811,7 +1810,7 @@
         pullop.repo.ui.status(_(b"no changes found\n"))
         pullop.cgresult = 0
     else:
-        if pullop.heads is None and list(pullop.common) == [nullid]:
+        if pullop.heads is None and list(pullop.common) == [pullop.repo.nullid]:
             pullop.repo.ui.status(_(b"requesting all changes\n"))
     if obsolete.isenabled(pullop.repo, obsolete.exchangeopt):
         remoteversions = bundle2.obsmarkersversion(pullop.remotebundle2caps)
@@ -1878,7 +1877,7 @@
         pullop.cgresult = 0
         return
     tr = pullop.gettransaction()
-    if pullop.heads is None and list(pullop.common) == [nullid]:
+    if pullop.heads is None and list(pullop.common) == [pullop.repo.nullid]:
         pullop.repo.ui.status(_(b"requesting all changes\n"))
     elif pullop.heads is None and pullop.remote.capable(b'changegroupsubset'):
         # issue1320, avoid a race if remote changed after discovery
@@ -2389,7 +2388,7 @@
     if not b2caps or b'bookmarks' not in b2caps:
         raise error.Abort(_(b'no common bookmarks exchange method'))
     books = bookmod.listbinbookmarks(repo)
-    data = bookmod.binaryencode(books)
+    data = bookmod.binaryencode(repo, books)
     if data:
         bundler.newpart(b'bookmarks', data=data)
 
diff --git a/mercurial/exchangev2.py b/mercurial/exchangev2.py
--- a/mercurial/exchangev2.py
+++ b/mercurial/exchangev2.py
@@ -11,10 +11,7 @@
 import weakref
 
 from .i18n import _
-from .node import (
-    nullid,
-    short,
-)
+from .node import short
 from . import (
     bookmarks,
     error,
@@ -297,7 +294,7 @@
         if set(remoteheads).issubset(common):
             fetch = []
 
-    common.discard(nullid)
+    common.discard(repo.nullid)
 
     return common, fetch, remoteheads
 
@@ -404,7 +401,7 @@
                 # Linknode is always itself for changesets.
                 cset[b'node'],
                 # We always send full revisions. So delta base is not set.
-                nullid,
+                repo.nullid,
                 mdiff.trivialdiffheader(len(data)) + data,
                 # Flags not yet supported.
                 0,
@@ -466,7 +463,7 @@
                 basenode = manifest[b'deltabasenode']
                 delta = extrafields[b'delta']
             elif b'revision' in extrafields:
-                basenode = nullid
+                basenode = repo.nullid
                 revision = extrafields[b'revision']
                 delta = mdiff.trivialdiffheader(len(revision)) + revision
             else:
@@ -596,7 +593,7 @@
                 basenode = filerevision[b'deltabasenode']
                 delta = extrafields[b'delta']
             elif b'revision' in extrafields:
-                basenode = nullid
+                basenode = repo.nullid
                 revision = extrafields[b'revision']
                 delta = mdiff.trivialdiffheader(len(revision)) + revision
             else:
@@ -689,7 +686,7 @@
                 basenode = filerevision[b'deltabasenode']
                 delta = extrafields[b'delta']
             elif b'revision' in extrafields:
-                basenode = nullid
+                basenode = repo.nullid
                 revision = extrafields[b'revision']
                 delta = mdiff.trivialdiffheader(len(revision)) + revision
             else:
diff --git a/mercurial/filelog.py b/mercurial/filelog.py
--- a/mercurial/filelog.py
+++ b/mercurial/filelog.py
@@ -8,10 +8,7 @@
 from __future__ import absolute_import
 
 from .i18n import _
-from .node import (
-    nullid,
-    nullrev,
-)
+from .node import nullrev
 from . import (
     error,
     revlog,
@@ -32,6 +29,7 @@
         # Full name of the user visible file, relative to the repository root.
         # Used by LFS.
         self._revlog.filename = path
+        self.nullid = self._revlog.nullid
 
     def __len__(self):
         return len(self._revlog)
@@ -40,7 +38,7 @@
         return self._revlog.__iter__()
 
     def hasnode(self, node):
-        if node in (nullid, nullrev):
+        if node in (self.nullid, nullrev):
             return False
 
         try:
diff --git a/mercurial/filemerge.py b/mercurial/filemerge.py
--- a/mercurial/filemerge.py
+++ b/mercurial/filemerge.py
@@ -15,7 +15,6 @@
 from .i18n import _
 from .node import (
     hex,
-    nullid,
     short,
 )
 from .pycompat import (
@@ -111,7 +110,7 @@
         return None
 
     def filenode(self):
-        return nullid
+        return self._ctx.repo().nullid
 
     _customcmp = True
 
diff --git a/mercurial/hg.py b/mercurial/hg.py
--- a/mercurial/hg.py
+++ b/mercurial/hg.py
@@ -14,7 +14,11 @@
 import stat
 
 from .i18n import _
-from .node import nullid
+from .node import (
+    hex,
+    sha1nodeconstants,
+    short,
+)
 from .pycompat import getattr
 
 from . import (
@@ -35,7 +39,6 @@
     merge as mergemod,
     mergestate as mergestatemod,
     narrowspec,
-    node,
     phases,
     pycompat,
     requirements,
@@ -108,7 +111,7 @@
                 raise error.Abort(_(b"dirstate branch not accessible"))
             branch = lrepo.dirstate.branch()
         if branch in branchmap:
-            revs.extend(node.hex(r) for r in reversed(branchmap[branch]))
+            revs.extend(hex(r) for r in reversed(branchmap[branch]))
             return True
         else:
             return False
@@ -754,8 +757,8 @@
                         b'lookup', {b'key': b'0',}
                     ).result()
 
-                if rootnode != node.nullid:
-                    sharepath = os.path.join(sharepool, node.hex(rootnode))
+                if rootnode != sha1nodeconstants.nullid:
+                    sharepath = os.path.join(sharepool, hex(rootnode))
                 else:
                     ui.status(
                         _(
@@ -772,7 +775,7 @@
                 )
         elif sharenamemode == b'remote':
             sharepath = os.path.join(
-                sharepool, node.hex(hashutil.sha1(source).digest())
+                sharepool, hex(hashutil.sha1(source).digest())
             )
         else:
             raise error.Abort(
@@ -864,9 +867,7 @@
             # we need to re-init the repo after manually copying the data
             # into it
             destpeer = peer(srcrepo, peeropts, dest)
-            srcrepo.hook(
-                b'outgoing', source=b'clone', node=node.hex(node.nullid)
-            )
+            srcrepo.hook(b'outgoing', source=b'clone', node=hex(srcrepo.nullid))
         else:
             try:
                 # only pass ui when no srcrepo
@@ -1263,7 +1264,9 @@
         for n in chlist:
             if limit is not None and count >= limit:
                 break
-            parents = [p for p in other.changelog.parents(n) if p != nullid]
+            parents = [
+                p for p in other.changelog.parents(n) if p != repo.nullid
+            ]
             if opts.get(b'no_merges') and len(parents) == 2:
                 continue
             count += 1
@@ -1321,7 +1324,7 @@
     for n in o:
         if limit is not None and count >= limit:
             break
-        parents = [p for p in repo.changelog.parents(n) if p != nullid]
+        parents = [p for p in repo.changelog.parents(n) if p != repo.nullid]
         if opts.get(b'no_merges') and len(parents) == 2:
             continue
         count += 1
@@ -1360,7 +1363,7 @@
             except Exception:
                 repo.ui.warn(
                     _(b'.hgsubstate is corrupt in revision %s\n')
-                    % node.short(ctx.node())
+                    % short(ctx.node())
                 )
 
     return ret
diff --git a/mercurial/hgweb/webutil.py b/mercurial/hgweb/webutil.py
--- a/mercurial/hgweb/webutil.py
+++ b/mercurial/hgweb/webutil.py
@@ -14,7 +14,7 @@
 import re
 
 from ..i18n import _
-from ..node import hex, nullid, short
+from ..node import hex, short
 from ..pycompat import setattr
 
 from .common import (
@@ -220,7 +220,7 @@
 def _siblings(siblings=None, hiderev=None):
     if siblings is None:
         siblings = []
-    siblings = [s for s in siblings if s.node() != nullid]
+    siblings = [s for s in siblings if s.node() != s.repo().nullid]
     if len(siblings) == 1 and siblings[0].rev() == hiderev:
         siblings = []
     return templateutil.mappinggenerator(_ctxsgen, args=(siblings,))
@@ -316,12 +316,16 @@
         yield {name: t}
 
 
-def showtag(repo, t1, node=nullid):
+def showtag(repo, t1, node=None):
+    if node is None:
+        node = repo.nullid
     args = (repo.nodetags, node, b'tag')
     return templateutil.mappinggenerator(_nodenamesgen, args=args, name=t1)
 
 
-def showbookmark(repo, t1, node=nullid):
+def showbookmark(repo, t1, node=None):
+    if node is None:
+        node = repo.nullid
     args = (repo.nodebookmarks, node, b'bookmark')
     return templateutil.mappinggenerator(_nodenamesgen, args=args, name=t1)
 
diff --git a/mercurial/interfaces/dirstate.py b/mercurial/interfaces/dirstate.py
--- a/mercurial/interfaces/dirstate.py
+++ b/mercurial/interfaces/dirstate.py
@@ -2,13 +2,11 @@
 
 import contextlib
 
-from .. import node as nodemod
-
 from . import util as interfaceutil
 
 
 class idirstate(interfaceutil.Interface):
-    def __init__(opener, ui, root, validate, sparsematchfn):
+    def __init__(opener, ui, root, validate, sparsematchfn, nodeconstants):
         '''Create a new dirstate object.
 
         opener is an open()-like callable that can be used to open the
@@ -97,7 +95,7 @@
     def branch():
         pass
 
-    def setparents(p1, p2=nodemod.nullid):
+    def setparents(p1, p2=None):
         """Set dirstate parents to p1 and p2.
 
         When moving from two parents to one, 'm' merged entries a
diff --git a/mercurial/interfaces/repository.py b/mercurial/interfaces/repository.py
--- a/mercurial/interfaces/repository.py
+++ b/mercurial/interfaces/repository.py
@@ -519,6 +519,10 @@
     * Metadata to facilitate storage.
     """
 
+    nullid = interfaceutil.Attribute(
+        """node for the null revision for use as delta base."""
+    )
+
     def __len__():
         """Obtain the number of revisions stored for this file."""
 
@@ -1133,6 +1137,10 @@
 class imanifeststorage(interfaceutil.Interface):
     """Storage interface for manifest data."""
 
+    nodeconstants = interfaceutil.Attribute(
+        """nodeconstants used by the current repository."""
+    )
+
     tree = interfaceutil.Attribute(
         """The path to the directory this manifest tracks.
 
@@ -1356,6 +1364,10 @@
     tree manifests.
     """
 
+    nodeconstants = interfaceutil.Attribute(
+        """nodeconstants used by the current repository."""
+    )
+
     def __getitem__(node):
         """Obtain a manifest instance for a given binary node.
 
@@ -1424,6 +1436,13 @@
     This currently captures the reality of things - not how things should be.
     """
 
+    nodeconstants = interfaceutil.Attribute(
+        """Constant nodes matching the hash function used by the repository."""
+    )
+    nullid = interfaceutil.Attribute(
+        """null revision for the hash function used by the repository."""
+    )
+
     supportedformats = interfaceutil.Attribute(
         """Set of requirements that apply to stream clone.
 
diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -19,8 +19,8 @@
 from .node import (
     bin,
     hex,
-    nullid,
     nullrev,
+    sha1nodeconstants,
     short,
 )
 from .pycompat import (
@@ -1195,6 +1195,8 @@
         self.vfs = hgvfs
         self.path = hgvfs.base
         self.requirements = requirements
+        self.nodeconstants = sha1nodeconstants
+        self.nullid = self.nodeconstants.nullid
         self.supported = supportedrequirements
         self.sharedpath = sharedpath
         self.store = store
@@ -1534,7 +1536,12 @@
         sparsematchfn = lambda: sparse.matcher(self)
 
         return dirstate.dirstate(
-            self.vfs, self.ui, self.root, self._dirstatevalidate, sparsematchfn
+            self.vfs,
+            self.ui,
+            self.root,
+            self._dirstatevalidate,
+            sparsematchfn,
+            self.nodeconstants,
         )
 
     def _dirstatevalidate(self, node):
@@ -1548,7 +1555,7 @@
                     _(b"warning: ignoring unknown working parent %s!\n")
                     % short(node)
                 )
-            return nullid
+            return self.nullid
 
     @storecache(narrowspec.FILENAME)
     def narrowpats(self):
@@ -1599,9 +1606,9 @@
     @unfilteredpropertycache
     def _quick_access_changeid_null(self):
         return {
-            b'null': (nullrev, nullid),
-            nullrev: (nullrev, nullid),
-            nullid: (nullrev, nullid),
+            b'null': (nullrev, self.nodeconstants.nullid),
+            nullrev: (nullrev, self.nodeconstants.nullid),
+            self.nullid: (nullrev, self.nullid),
         }
 
     @unfilteredpropertycache
@@ -1611,7 +1618,7 @@
         quick = self._quick_access_changeid_null.copy()
         cl = self.unfiltered().changelog
         for node in self.dirstate.parents():
-            if node == nullid:
+            if node == self.nullid:
                 continue
             rev = cl.index.get_rev(node)
             if rev is None:
@@ -1631,7 +1638,7 @@
                 quick[r] = pair
                 quick[n] = pair
         p1node = self.dirstate.p1()
-        if p1node != nullid:
+        if p1node != self.nullid:
             quick[b'.'] = quick[p1node]
         return quick
 
@@ -1887,7 +1894,7 @@
         # local encoding.
         tags = {}
         for (name, (node, hist)) in pycompat.iteritems(alltags):
-            if node != nullid:
+            if node != self.nullid:
                 tags[encoding.tolocal(name)] = node
         tags[b'tip'] = self.changelog.tip()
         tagtypes = {
@@ -2008,7 +2015,9 @@
     def wjoin(self, f, *insidef):
         return self.vfs.reljoin(self.root, f, *insidef)
 
-    def setparents(self, p1, p2=nullid):
+    def setparents(self, p1, p2=None):
+        if p2 is None:
+            p2 = self.nullid
         self[None].setparents(p1, p2)
         self._quick_access_changeid_invalidate()
 
@@ -2922,7 +2931,7 @@
                 subrepoutil.writestate(self, newstate)
 
             p1, p2 = self.dirstate.parents()
-            hookp1, hookp2 = hex(p1), (p2 != nullid and hex(p2) or b'')
+            hookp1, hookp2 = hex(p1), (p2 != self.nullid and hex(p2) or b'')
             try:
                 self.hook(
                     b"precommit", throw=True, parent1=hookp1, parent2=hookp2
@@ -3095,7 +3104,7 @@
             t = n
             while True:
                 p = self.changelog.parents(n)
-                if p[1] != nullid or p[0] == nullid:
+                if p[1] != self.nullid or p[0] == self.nullid:
                     b.append((t, n, p[0], p[1]))
                     break
                 n = p[0]
@@ -3108,7 +3117,7 @@
             n, l, i = top, [], 0
             f = 1
 
-            while n != bottom and n != nullid:
+            while n != bottom and n != self.nullid:
                 p = self.changelog.parents(n)[0]
                 if i == f:
                     l.append(n)
diff --git a/mercurial/logcmdutil.py b/mercurial/logcmdutil.py
--- a/mercurial/logcmdutil.py
+++ b/mercurial/logcmdutil.py
@@ -12,11 +12,7 @@
 import posixpath
 
 from .i18n import _
-from .node import (
-    nullid,
-    wdirid,
-    wdirrev,
-)
+from .node import wdirrev
 
 from .thirdparty import attr
 
@@ -324,7 +320,7 @@
         if self.ui.debugflag:
             mnode = ctx.manifestnode()
             if mnode is None:
-                mnode = wdirid
+                mnode = self.repo.nodeconstants.wdirid
                 mrev = wdirrev
             else:
                 mrev = self.repo.manifestlog.rev(mnode)
@@ -473,7 +469,11 @@
         )
 
         if self.ui.debugflag or b'manifest' in datahint:
-            fm.data(manifest=fm.hexfunc(ctx.manifestnode() or wdirid))
+            fm.data(
+                manifest=fm.hexfunc(
+                    ctx.manifestnode() or self.repo.nodeconstants.wdirid
+                )
+            )
         if self.ui.debugflag or b'extra' in datahint:
             fm.data(extra=fm.formatdict(ctx.extra()))
 
@@ -949,7 +949,7 @@
     """Return the initial set of revisions to be filtered or followed"""
     if wopts.revspec:
         revs = scmutil.revrange(repo, wopts.revspec)
-    elif wopts.follow and repo.dirstate.p1() == nullid:
+    elif wopts.follow and repo.dirstate.p1() == repo.nullid:
         revs = smartset.baseset()
     elif wopts.follow:
         revs = repo.revs(b'.')
diff --git a/mercurial/manifest.py b/mercurial/manifest.py
--- a/mercurial/manifest.py
+++ b/mercurial/manifest.py
@@ -16,7 +16,6 @@
 from .node import (
     bin,
     hex,
-    nullid,
     nullrev,
 )
 from .pycompat import getattr
@@ -792,9 +791,13 @@
 
 @interfaceutil.implementer(repository.imanifestdict)
 class treemanifest(object):
-    def __init__(self, dir=b'', text=b''):
+    def __init__(self, nodeconstants, dir=b'', text=b''):
         self._dir = dir
-        self._node = nullid
+        self.nodeconstants = nodeconstants
+        from .node import sha1nodeconstants
+
+        assert sha1nodeconstants == nodeconstants
+        self._node = self.nodeconstants.nullid
         self._loadfunc = _noop
         self._copyfunc = _noop
         self._dirty = False
@@ -1050,7 +1053,9 @@
         if dir:
             self._loadlazy(dir)
             if dir not in self._dirs:
-                self._dirs[dir] = treemanifest(self._subpath(dir))
+                self._dirs[dir] = treemanifest(
+                    self.nodeconstants, self._subpath(dir)
+                )
             self._dirs[dir].__setitem__(subpath, n)
         else:
             # manifest nodes are either 20 bytes or 32 bytes,
@@ -1077,14 +1082,16 @@
         if dir:
             self._loadlazy(dir)
             if dir not in self._dirs:
-                self._dirs[dir] = treemanifest(self._subpath(dir))
+                self._dirs[dir] = treemanifest(
+                    self.nodeconstants, self._subpath(dir)
+                )
             self._dirs[dir].setflag(subpath, flags)
         else:
             self._flags[f] = flags
         self._dirty = True
 
     def copy(self):
-        copy = treemanifest(self._dir)
+        copy = treemanifest(self.nodeconstants, self._dir)
         copy._node = self._node
         copy._dirty = self._dirty
         if self._copyfunc is _noop:
@@ -1215,7 +1222,7 @@
         visit = match.visitchildrenset(self._dir[:-1])
         if visit == b'all':
             return self.copy()
-        ret = treemanifest(self._dir)
+        ret = treemanifest(self.nodeconstants, self._dir)
         if not visit:
             return ret
 
@@ -1272,7 +1279,7 @@
             m2 = m2._matches(match)
             return m1.diff(m2, clean=clean)
         result = {}
-        emptytree = treemanifest()
+        emptytree = treemanifest(self.nodeconstants)
 
         def _iterativediff(t1, t2, stack):
             """compares two tree manifests and append new tree-manifests which
@@ -1369,7 +1376,7 @@
         self._load()  # for consistency; should never have any effect here
         m1._load()
         m2._load()
-        emptytree = treemanifest()
+        emptytree = treemanifest(self.nodeconstants)
 
         def getnode(m, d):
             ld = m._lazydirs.get(d)
@@ -1387,7 +1394,7 @@
                 continue
             subp1 = getnode(m1, d)
             subp2 = getnode(m2, d)
-            if subp1 == nullid:
+            if subp1 == self.nodeconstants.nullid:
                 subp1, subp2 = subp2, subp1
             writesubtree(subm, subp1, subp2, match)
 
@@ -1552,6 +1559,7 @@
 
     def __init__(
         self,
+        nodeconstants,
         opener,
         tree=b'',
         dirlogcache=None,
@@ -1568,6 +1576,13 @@
         option takes precedence, so if it is set to True, we ignore whatever
         value is passed in to the constructor.
         """
+        self.nodeconstants = nodeconstants
+        from .node import sha1nodeconstants
+
+        assert sha1nodeconstants == nodeconstants, (
+            sha1nodeconstants,
+            nodeconstants,
+        )
         # During normal operations, we expect to deal with not more than four
         # revs at a time (such as during commit --amend). When rebasing large
         # stacks of commits, the number can go up, hence the config knob below.
@@ -1654,7 +1669,11 @@
             assert self._treeondisk
         if d not in self._dirlogcache:
             mfrevlog = manifestrevlog(
-                self.opener, d, self._dirlogcache, treemanifest=self._treeondisk
+                self.nodeconstants,
+                self.opener,
+                d,
+                self._dirlogcache,
+                treemanifest=self._treeondisk,
             )
             self._dirlogcache[d] = mfrevlog
         return self._dirlogcache[d]
@@ -1910,6 +1929,10 @@
     they receive (i.e. tree or flat or lazily loaded, etc)."""
 
     def __init__(self, opener, repo, rootstore, narrowmatch):
+        self.nodeconstants = repo.nodeconstants
+        from .node import sha1nodeconstants
+
+        assert sha1nodeconstants == repo.nodeconstants
         usetreemanifest = False
         cachesize = 4
 
@@ -1948,7 +1971,7 @@
 
         if not self._narrowmatch.always():
             if not self._narrowmatch.visitdir(tree[:-1]):
-                return excludeddirmanifestctx(tree, node)
+                return excludeddirmanifestctx(self.nodeconstants, tree, node)
         if tree:
             if self._rootstore._treeondisk:
                 if verify:
@@ -1975,7 +1998,7 @@
             else:
                 m = manifestctx(self, node)
 
-        if node != nullid:
+        if node != self.nodeconstants.nullid:
             mancache = self._dirmancache.get(tree)
             if not mancache:
                 mancache = util.lrucachedict(self._cachesize)
@@ -2063,7 +2086,7 @@
 
     def read(self):
         if self._data is None:
-            if self._node == nullid:
+            if self._node == self._manifestlog.nodeconstants.nullid:
                 self._data = manifestdict()
             else:
                 store = self._storage()
@@ -2111,7 +2134,7 @@
     def __init__(self, manifestlog, dir=b''):
         self._manifestlog = manifestlog
         self._dir = dir
-        self._treemanifest = treemanifest()
+        self._treemanifest = treemanifest(manifestlog.nodeconstants)
 
     def _storage(self):
         return self._manifestlog.getstorage(b'')
@@ -2161,17 +2184,19 @@
         narrowmatch = self._manifestlog._narrowmatch
         if not narrowmatch.always():
             if not narrowmatch.visitdir(self._dir[:-1]):
-                return excludedmanifestrevlog(self._dir)
+                return excludedmanifestrevlog(
+                    self._manifestlog.nodeconstants, self._dir
+                )
         return self._manifestlog.getstorage(self._dir)
 
     def read(self):
         if self._data is None:
             store = self._storage()
-            if self._node == nullid:
-                self._data = treemanifest()
+            if self._node == self._manifestlog.nodeconstants.nullid:
+                self._data = treemanifest(self._manifestlog.nodeconstants)
             # TODO accessing non-public API
             elif store._treeondisk:
-                m = treemanifest(dir=self._dir)
+                m = treemanifest(self._manifestlog.nodeconstants, dir=self._dir)
 
                 def gettext():
                     return store.revision(self._node)
@@ -2191,7 +2216,9 @@
                     text = store.revision(self._node)
                     arraytext = bytearray(text)
                     store.fulltextcache[self._node] = arraytext
-                self._data = treemanifest(dir=self._dir, text=text)
+                self._data = treemanifest(
+                    self._manifestlog.nodeconstants, dir=self._dir, text=text
+                )
 
         return self._data
 
@@ -2228,7 +2255,7 @@
             r0 = store.deltaparent(store.rev(self._node))
             m0 = self._manifestlog.get(self._dir, store.node(r0)).read()
             m1 = self.read()
-            md = treemanifest(dir=self._dir)
+            md = treemanifest(self._manifestlog.nodeconstants, dir=self._dir)
             for f, ((n0, fl0), (n1, fl1)) in pycompat.iteritems(m0.diff(m1)):
                 if n1:
                     md[f] = n1
@@ -2271,8 +2298,11 @@
     whose contents are unknown.
     """
 
-    def __init__(self, dir, node):
-        super(excludeddir, self).__init__(dir)
+    def __init__(self, nodeconstants, dir, node):
+        super(excludeddir, self).__init__(nodeconstants, dir)
+        from .node import sha1nodeconstants
+
+        assert sha1nodeconstants == nodeconstants
         self._node = node
         # Add an empty file, which will be included by iterators and such,
         # appearing as the directory itself (i.e. something like "dir/")
@@ -2291,12 +2321,16 @@
 class excludeddirmanifestctx(treemanifestctx):
     """context wrapper for excludeddir - see that docstring for rationale"""
 
-    def __init__(self, dir, node):
+    def __init__(self, nodeconstants, dir, node):
+        self.nodeconstants = nodeconstants
+        from .node import sha1nodeconstants
+
+        assert sha1nodeconstants == nodeconstants
         self._dir = dir
         self._node = node
 
     def read(self):
-        return excludeddir(self._dir, self._node)
+        return excludeddir(self.nodeconstants, self._dir, self._node)
 
     def write(self, *args):
         raise error.ProgrammingError(
@@ -2314,7 +2348,11 @@
     outside the narrowspec.
     """
 
-    def __init__(self, dir):
+    def __init__(self, nodeconstants, dir):
+        self.nodeconstants = nodeconstants
+        from .node import sha1nodeconstants
+
+        assert sha1nodeconstants == nodeconstants
         self._dir = dir
 
     def __len__(self):
diff --git a/mercurial/merge.py b/mercurial/merge.py
--- a/mercurial/merge.py
+++ b/mercurial/merge.py
@@ -13,12 +13,7 @@
 import struct
 
 from .i18n import _
-from .node import (
-    addednodeid,
-    modifiednodeid,
-    nullid,
-    nullrev,
-)
+from .node import nullrev
 from .thirdparty import attr
 from . import (
     copies,
@@ -770,7 +765,7 @@
         # to flag the change. If wctx is a committed revision, we shouldn't
         # care for the dirty state of the working directory.
         if any(wctx.sub(s).dirty() for s in wctx.substate):
-            m1[b'.hgsubstate'] = modifiednodeid
+            m1[b'.hgsubstate'] = repo.nodeconstants.modifiednodeid
 
     # Don't use m2-vs-ma optimization if:
     # - ma is the same as m1 or m2, which we're just going to diff again later
@@ -932,7 +927,7 @@
                             mresult.addcommitinfo(
                                 f, b'merge-removal-candidate', b'yes'
                             )
-                elif n1 == addednodeid:
+                elif n1 == repo.nodeconstants.addednodeid:
                     # This file was locally added. We should forget it instead of
                     # deleting it.
                     mresult.addfile(
@@ -1752,7 +1747,7 @@
     if (
         fsmonitorwarning
         and not fsmonitorenabled
-        and p1node == nullid
+        and p1node == repo.nullid
         and num_gets >= fsmonitorthreshold
         and pycompat.sysplatform.startswith((b'linux', b'darwin'))
     ):
@@ -1880,7 +1875,7 @@
         else:
             if repo.ui.configlist(b'merge', b'preferancestor') == [b'*']:
                 cahs = repo.changelog.commonancestorsheads(p1.node(), p2.node())
-                pas = [repo[anc] for anc in (sorted(cahs) or [nullid])]
+                pas = [repo[anc] for anc in (sorted(cahs) or [repo.nullid])]
             else:
                 pas = [p1.ancestor(p2, warn=branchmerge)]
 
@@ -2073,7 +2068,7 @@
 
         ### apply phase
         if not branchmerge:  # just jump to the new rev
-            fp1, fp2, xp1, xp2 = fp2, nullid, xp2, b''
+            fp1, fp2, xp1, xp2 = fp2, repo.nullid, xp2, b''
         # If we're doing a partial update, we need to skip updating
         # the dirstate.
         always = matcher is None or matcher.always()
@@ -2236,14 +2231,14 @@
     if keepconflictparent and stats.unresolvedcount:
         pother = ctx.node()
     else:
-        pother = nullid
+        pother = repo.nullid
         parents = ctx.parents()
         if keepparent and len(parents) == 2 and base in parents:
             parents.remove(base)
             pother = parents[0].node()
     # Never set both parents equal to each other
     if pother == pctx.node():
-        pother = nullid
+        pother = repo.nullid
 
     if wctx.isinmemory():
         wctx.setparents(pctx.node(), pother)
diff --git a/mercurial/mergestate.py b/mercurial/mergestate.py
--- a/mercurial/mergestate.py
+++ b/mercurial/mergestate.py
@@ -9,8 +9,6 @@
 from .node import (
     bin,
     hex,
-    nullhex,
-    nullid,
 )
 from . import (
     error,
@@ -32,7 +30,7 @@
 
 
 def _filectxorabsent(hexnode, ctx, f):
-    if hexnode == nullhex:
+    if hexnode == ctx.repo().nodeconstants.nullhex:
         return filemerge.absentfilectx(ctx, f)
     else:
         return ctx[f]
@@ -248,7 +246,7 @@
         note: also write the local version to the `.hg/merge` directory.
         """
         if fcl.isabsent():
-            localkey = nullhex
+            localkey = self._repo.nodeconstants.nullhex
         else:
             localkey = mergestate.getlocalkey(fcl.path())
             self._make_backup(fcl, localkey)
@@ -341,7 +339,7 @@
         flo = fco.flags()
         fla = fca.flags()
         if b'x' in flags + flo + fla and b'l' not in flags + flo + fla:
-            if fca.node() == nullid and flags != flo:
+            if fca.node() == self._repo.nullid and flags != flo:
                 if preresolve:
                     self._repo.ui.warn(
                         _(
@@ -354,7 +352,7 @@
                 flags = flo
         if preresolve:
             # restore local
-            if localkey != nullhex:
+            if localkey != self._repo.nodeconstants.nullhex:
                 self._restore_backup(wctx[dfile], localkey, flags)
             else:
                 wctx[dfile].remove(ignoremissing=True)
@@ -659,7 +657,10 @@
                 records.append(
                     (RECORD_PATH_CONFLICT, b'\0'.join([filename] + v))
                 )
-            elif v[1] == nullhex or v[6] == nullhex:
+            elif (
+                v[1] == self._repo.nodeconstants.nullhex
+                or v[6] == self._repo.nodeconstants.nullhex
+            ):
                 # Change/Delete or Delete/Change conflicts. These are stored in
                 # 'C' records. v[1] is the local file, and is nullhex when the
                 # file is deleted locally ('dc'). v[6] is the remote file, and
diff --git a/mercurial/metadata.py b/mercurial/metadata.py
--- a/mercurial/metadata.py
+++ b/mercurial/metadata.py
@@ -11,9 +11,9 @@
 import multiprocessing
 import struct
 
+from .node import nullrev
 from . import (
     error,
-    node,
     pycompat,
     util,
 )
@@ -239,11 +239,11 @@
     """compute the files changed by a revision"""
     p1 = ctx.p1()
     p2 = ctx.p2()
-    if p1.rev() == node.nullrev and p2.rev() == node.nullrev:
+    if p1.rev() == nullrev and p2.rev() == nullrev:
         return _process_root(ctx)
-    elif p1.rev() != node.nullrev and p2.rev() == node.nullrev:
+    elif p1.rev() != nullrev and p2.rev() == nullrev:
         return _process_linear(p1, ctx)
-    elif p1.rev() == node.nullrev and p2.rev() != node.nullrev:
+    elif p1.rev() == nullrev and p2.rev() != nullrev:
         # In the wild, one can encounter changeset where p1 is null but p2 is not
         return _process_linear(p1, ctx, parent=2)
     elif p1.rev() == p2.rev():
@@ -425,7 +425,7 @@
         p1_ctx.node(), p2_ctx.node()
     )
     if not cahs:
-        cahs = [node.nullrev]
+        cahs = [nullrev]
     mas = [ctx.repo()[r].manifest() for r in cahs]
 
     copy_candidates = []
@@ -563,7 +563,7 @@
         p2n = p2.node()
         cahs = ctx.repo().changelog.commonancestorsheads(p1n, p2n)
         if not cahs:
-            cahs = [node.nullrev]
+            cahs = [nullrev]
         return [ctx.repo()[r].manifest() for r in cahs]
 
     def deletionfromparent(f):
@@ -602,7 +602,7 @@
         if f in ctx:
             fctx = ctx[f]
             parents = fctx._filelog.parents(fctx._filenode)
-            if parents[1] != node.nullid:
+            if parents[1] != ctx.repo().nullid:
                 merged.append(f)
     return merged
 
diff --git a/mercurial/node.py b/mercurial/node.py
--- a/mercurial/node.py
+++ b/mercurial/node.py
@@ -22,28 +22,46 @@
 
 
 nullrev = -1
-# In hex, this is '0000000000000000000000000000000000000000'
-nullid = b"\0" * 20
-nullhex = hex(nullid)
+
+# pseudo identifier for working directory
+# (experimental, so don't add too many dependencies on it)
+wdirrev = 0x7FFFFFFF
+
+
+class sha1nodeconstants(object):
+    # In hex, this is '0000000000000000000000000000000000000000'
+    nullid = b"\0" * 20
+    nullhex = hex(nullid)
 
-# Phony node value to stand-in for new files in some uses of
-# manifests.
-# In hex, this is '2121212121212121212121212121212121212121'
-newnodeid = b'!!!!!!!!!!!!!!!!!!!!'
-# In hex, this is '3030303030303030303030303030306164646564'
-addednodeid = b'000000000000000added'
-# In hex, this is '3030303030303030303030306d6f646966696564'
-modifiednodeid = b'000000000000modified'
+    # Phony node value to stand-in for new files in some uses of
+    # manifests.
+    # In hex, this is '2121212121212121212121212121212121212121'
+    newnodeid = b'!!!!!!!!!!!!!!!!!!!!'
+    # In hex, this is '3030303030303030303030303030306164646564'
+    addednodeid = b'000000000000000added'
+    # In hex, this is '3030303030303030303030306d6f646966696564'
+    modifiednodeid = b'000000000000modified'
 
-wdirfilenodeids = {newnodeid, addednodeid, modifiednodeid}
+    wdirfilenodeids = {newnodeid, addednodeid, modifiednodeid}
 
-# pseudo identifiers for working directory
-# (they are experimental, so don't add too many dependencies on them)
-wdirrev = 0x7FFFFFFF
-# In hex, this is 'ffffffffffffffffffffffffffffffffffffffff'
-wdirid = b"\xff" * 20
-wdirhex = hex(wdirid)
+    # pseudo identifier for working directory
+    # (experimental, so don't add too many dependencies on it)
+    # In hex, this is 'ffffffffffffffffffffffffffffffffffffffff'
+    wdirid = b"\xff" * 20
+    wdirhex = hex(wdirid)
 
 
 def short(node):
     return hex(node[:6])
+
+
+# legacy starting point for porting modules
+#
+# nullid = sha1nodeconstants.nullid
+# nullhex = sha1nodeconstants.nullhex
+# newnodeid = sha1nodeconstants.newnodeid
+# addednodeid = sha1nodeconstants.addednodeid
+# modifiednodeid = sha1nodeconstants.modifiednodeid
+# wdirfilenodeids = sha1nodeconstants.wdirfilenodeids
+# wdirid = sha1nodeconstants.wdirid
+# wdirhex = sha1nodeconstants.wdirhex
diff --git a/mercurial/obsolete.py b/mercurial/obsolete.py
--- a/mercurial/obsolete.py
+++ b/mercurial/obsolete.py
@@ -73,11 +73,14 @@
 import struct
 
 from .i18n import _
+from .node import (
+    bin,
+    hex,
+)
 from .pycompat import getattr
 from . import (
     encoding,
     error,
-    node,
     obsutil,
     phases,
     policy,
@@ -235,7 +238,7 @@
             parents = ()
         if parents is not None:
             try:
-                parents = tuple(node.bin(p) for p in parents)
+                parents = tuple(bin(p) for p in parents)
                 # if parent content is not a nodeid, drop the data
                 for p in parents:
                     if len(p) != 20:
@@ -262,7 +265,7 @@
             # mark that we explicitly recorded no parents
             metadata[b'p0'] = b''
         for i, p in enumerate(parents, 1):
-            metadata[b'p%i' % i] = node.hex(p)
+            metadata[b'p%i' % i] = hex(p)
     metadata = _fm0encodemeta(metadata)
     numsuc = len(sucs)
     format = _fm0fixed + (_fm0node * numsuc)
@@ -522,14 +525,14 @@
                 children.setdefault(p, set()).add(mark)
 
 
-def _checkinvalidmarkers(markers):
+def _checkinvalidmarkers(repo, markers):
     """search for marker with invalid data and raise error if needed
 
     Exist as a separated function to allow the evolve extension for a more
     subtle handling.
     """
     for mark in markers:
-        if node.nullid in mark[1]:
+        if repo.nullid in mark[1]:
             raise error.Abort(
                 _(
                     b'bad obsolescence marker detected: '
@@ -556,10 +559,11 @@
     # parents: (tuple of nodeid) or None, parents of predecessors
     #          None is used when no data has been recorded
 
-    def __init__(self, svfs, defaultformat=_fm1version, readonly=False):
+    def __init__(self, repo, svfs, defaultformat=_fm1version, readonly=False):
         # caches for various obsolescence related cache
         self.caches = {}
         self.svfs = svfs
+        self.repo = repo
         self._defaultformat = defaultformat
         self._readonly = readonly
 
@@ -639,7 +643,7 @@
                     raise ValueError(succ)
         if prec in succs:
             raise ValueError(
-                'in-marker cycle with %s' % pycompat.sysstr(node.hex(prec))
+                'in-marker cycle with %s' % pycompat.sysstr(hex(prec))
             )
 
         metadata = tuple(sorted(pycompat.iteritems(metadata)))
@@ -722,7 +726,7 @@
             return []
         self._version, markers = _readmarkers(data)
         markers = list(markers)
-        _checkinvalidmarkers(markers)
+        _checkinvalidmarkers(self.repo, markers)
         return markers
 
     @propertycache
@@ -756,7 +760,7 @@
             _addpredecessors(self.predecessors, markers)
         if self._cached('children'):
             _addchildren(self.children, markers)
-        _checkinvalidmarkers(markers)
+        _checkinvalidmarkers(self.repo, markers)
 
     def relevantmarkers(self, nodes):
         """return a set of all obsolescence markers relevant to a set of nodes.
@@ -802,7 +806,7 @@
     if defaultformat is not None:
         kwargs['defaultformat'] = defaultformat
     readonly = not isenabled(repo, createmarkersopt)
-    store = obsstore(repo.svfs, readonly=readonly, **kwargs)
+    store = obsstore(repo, repo.svfs, readonly=readonly, **kwargs)
     if store and readonly:
         ui.warn(
             _(b'obsolete feature not enabled but %i markers found!\n')
@@ -1032,7 +1036,7 @@
         folddigest.update(p.node())
     # Since fold only has to compete against fold for the same successors, it
     # seems fine to use a small ID. Smaller ID save space.
-    return node.hex(folddigest.digest())[:8]
+    return hex(folddigest.digest())[:8]
 
 
 def createmarkers(
diff --git a/mercurial/obsutil.py b/mercurial/obsutil.py
--- a/mercurial/obsutil.py
+++ b/mercurial/obsutil.py
@@ -10,11 +10,14 @@
 import re
 
 from .i18n import _
+from .node import (
+    hex,
+    short,
+)
 from . import (
     diffutil,
     encoding,
     error,
-    node as nodemod,
     phases,
     pycompat,
     util,
@@ -961,13 +964,13 @@
     elif fate == b'diverged':
         return filteredmsgtable[b'diverged'] % changeid
     elif fate == b'superseded':
-        single_successor = nodemod.short(successors[0][0])
+        single_successor = short(successors[0][0])
         return filteredmsgtable[b'superseded'] % (changeid, single_successor)
     elif fate == b'superseded_split':
 
         succs = []
         for node_id in successors[0]:
-            succs.append(nodemod.short(node_id))
+            succs.append(short(node_id))
 
         if len(succs) <= 2:
             fmtsuccs = b', '.join(succs)
@@ -1044,7 +1047,7 @@
                     b'instability': b'content-divergent',
                     b'divergentnodes': divnodes,
                     b'reason': b'predecessor',
-                    b'node': nodemod.hex(dset[b'commonpredecessor']),
+                    b'node': hex(dset[b'commonpredecessor']),
                 }
             )
     return result
diff --git a/mercurial/phases.py b/mercurial/phases.py
--- a/mercurial/phases.py
+++ b/mercurial/phases.py
@@ -109,7 +109,6 @@
 from .node import (
     bin,
     hex,
-    nullid,
     nullrev,
     short,
     wdirrev,
@@ -826,7 +825,7 @@
         node = bin(nhex)
         phase = int(phase)
         if phase == public:
-            if node != nullid:
+            if node != repo.nullid:
                 repo.ui.warn(
                     _(
                         b'ignoring inconsistent public root'
@@ -883,10 +882,10 @@
     rev = cl.index.get_rev
     if not roots:
         return heads
-    if not heads or heads == [nullid]:
+    if not heads or heads == [repo.nullid]:
         return []
     # The logic operated on revisions, convert arguments early for convenience
-    new_heads = {rev(n) for n in heads if n != nullid}
+    new_heads = {rev(n) for n in heads if n != repo.nullid}
     roots = [rev(n) for n in roots]
     # compute the area we need to remove
     affected_zone = repo.revs(b"(%ld::%ld)", roots, new_heads)
diff --git a/mercurial/pure/parsers.py b/mercurial/pure/parsers.py
--- a/mercurial/pure/parsers.py
+++ b/mercurial/pure/parsers.py
@@ -10,7 +10,10 @@
 import struct
 import zlib
 
-from ..node import nullid, nullrev
+from ..node import (
+    nullrev,
+    sha1nodeconstants,
+)
 from .. import (
     pycompat,
     util,
@@ -37,7 +40,7 @@
 indexfirst = struct.calcsize(b'Q')
 sizeint = struct.calcsize(b'i')
 indexsize = struct.calcsize(indexformatng)
-nullitem = (0, 0, 0, -1, -1, -1, -1, nullid)
+nullitem = (0, 0, 0, -1, -1, -1, -1, sha1nodeconstants.nullid)
 
 
 def gettype(q):
@@ -57,7 +60,7 @@
 
     @util.propertycache
     def _nodemap(self):
-        nodemap = nodemaputil.NodeMap({nullid: nullrev})
+        nodemap = nodemaputil.NodeMap({sha1nodeconstants.nullid: nullrev})
         for r in range(0, len(self)):
             n = self[r][7]
             nodemap[n] = r
diff --git a/mercurial/revlog.py b/mercurial/revlog.py
--- a/mercurial/revlog.py
+++ b/mercurial/revlog.py
@@ -25,13 +25,9 @@
 from .node import (
     bin,
     hex,
-    nullhex,
-    nullid,
     nullrev,
+    sha1nodeconstants,
     short,
-    wdirfilenodeids,
-    wdirhex,
-    wdirid,
     wdirrev,
 )
 from .i18n import _
@@ -226,7 +222,7 @@
 
     @util.propertycache
     def _nodemap(self):
-        nodemap = nodemaputil.NodeMap({nullid: nullrev})
+        nodemap = nodemaputil.NodeMap({sha1nodeconstants.nullid: nullrev})
         for r in range(0, len(self)):
             n = self[r][7]
             nodemap[n] = r
@@ -264,7 +260,7 @@
 
     def __getitem__(self, i):
         if i == -1:
-            return (0, 0, 0, -1, -1, -1, -1, nullid)
+            return (0, 0, 0, -1, -1, -1, -1, sha1nodeconstants.nullid)
         return list.__getitem__(self, i)
 
 
@@ -275,7 +271,7 @@
     def parseindex(self, data, inline):
         s = self.size
         index = []
-        nodemap = nodemaputil.NodeMap({nullid: nullrev})
+        nodemap = nodemaputil.NodeMap({sha1nodeconstants.nullid: nullrev})
         n = off = 0
         l = len(data)
         while off + s <= l:
@@ -615,6 +611,10 @@
             raise error.RevlogError(
                 _(b'unknown version (%d) in revlog %s') % (fmt, self.indexfile)
             )
+
+        self.nodeconstants = sha1nodeconstants
+        self.nullid = self.nodeconstants.nullid
+
         # sparse-revlog can't be on without general-delta (issue6056)
         if not self._generaldelta:
             self._sparserevlog = False
@@ -804,7 +804,10 @@
             raise
         except error.RevlogError:
             # parsers.c radix tree lookup failed
-            if node == wdirid or node in wdirfilenodeids:
+            if (
+                node == self.nodeconstants.wdirid
+                or node in self.nodeconstants.wdirfilenodeids
+            ):
                 raise error.WdirUnsupported
             raise error.LookupError(node, self.indexfile, _(b'no node'))
 
@@ -1002,7 +1005,7 @@
         not supplied, uses all of the revlog's heads.  If common is not
         supplied, uses nullid."""
         if common is None:
-            common = [nullid]
+            common = [self.nullid]
         if heads is None:
             heads = self.heads()
 
@@ -1108,7 +1111,7 @@
         not supplied, uses all of the revlog's heads.  If common is not
         supplied, uses nullid."""
         if common is None:
-            common = [nullid]
+            common = [self.nullid]
         if heads is None:
             heads = self.heads()
 
@@ -1146,11 +1149,15 @@
                 return nonodes
             lowestrev = min([self.rev(n) for n in roots])
         else:
-            roots = [nullid]  # Everybody's a descendant of nullid
+            roots = [self.nullid]  # Everybody's a descendant of nullid
             lowestrev = nullrev
         if (lowestrev == nullrev) and (heads is None):
             # We want _all_ the nodes!
-            return ([self.node(r) for r in self], [nullid], list(self.heads()))
+            return (
+                [self.node(r) for r in self],
+                [self.nullid],
+                list(self.heads()),
+            )
         if heads is None:
             # All nodes are ancestors, so the latest ancestor is the last
             # node.
@@ -1176,7 +1183,7 @@
                 # grab a node to tag
                 n = nodestotag.pop()
                 # Never tag nullid
-                if n == nullid:
+                if n == self.nullid:
                     continue
                 # A node's revision number represents its place in a
                 # topologically sorted list of nodes.
@@ -1188,7 +1195,7 @@
                         ancestors.add(n)  # Mark as ancestor
                         # Add non-nullid parents to list of nodes to tag.
                         nodestotag.update(
-                            [p for p in self.parents(n) if p != nullid]
+                            [p for p in self.parents(n) if p != self.nullid]
                         )
                     elif n in heads:  # We've seen it before, is it a fake head?
                         # So it is, real heads should not be the ancestors of
@@ -1216,7 +1223,7 @@
                 # We are descending from nullid, and don't need to care about
                 # any other roots.
                 lowestrev = nullrev
-                roots = [nullid]
+                roots = [self.nullid]
         # Transform our roots list into a set.
         descendants = set(roots)
         # Also, keep the original roots so we can filter out roots that aren't
@@ -1310,7 +1317,7 @@
         """
         if start is None and stop is None:
             if not len(self):
-                return [nullid]
+                return [self.nullid]
             return [self.node(r) for r in self.headrevs()]
 
         if start is None:
@@ -1400,7 +1407,7 @@
         if ancs:
             # choose a consistent winner when there's a tie
             return min(map(self.node, ancs))
-        return nullid
+        return self.nullid
 
     def _match(self, id):
         if isinstance(id, int):
@@ -1438,7 +1445,7 @@
 
     def _partialmatch(self, id):
         # we don't care wdirfilenodeids as they should be always full hash
-        maybewdir = wdirhex.startswith(id)
+        maybewdir = self.nodeconstants.wdirhex.startswith(id)
         try:
             partial = self.index.partialmatch(id)
             if partial and self.hasnode(partial):
@@ -1474,8 +1481,8 @@
                 nl = [
                     n for n in nl if hex(n).startswith(id) and self.hasnode(n)
                 ]
-                if nullhex.startswith(id):
-                    nl.append(nullid)
+                if self.nodeconstants.nullhex.startswith(id):
+                    nl.append(self.nullid)
                 if len(nl) > 0:
                     if len(nl) == 1 and not maybewdir:
                         self._pcache[id] = nl[0]
@@ -1535,13 +1542,13 @@
                 length = max(self.index.shortest(node), minlength)
                 return disambiguate(hexnode, length)
             except error.RevlogError:
-                if node != wdirid:
+                if node != self.nodeconstants.wdirid:
                     raise error.LookupError(node, self.indexfile, _(b'no node'))
             except AttributeError:
                 # Fall through to pure code
                 pass
 
-        if node == wdirid:
+        if node == self.nodeconstants.wdirid:
             for length in range(minlength, len(hexnode) + 1):
                 prefix = hexnode[:length]
                 if isvalid(prefix):
@@ -1857,7 +1864,7 @@
             rev = None
 
         # fast path the special `nullid` rev
-        if node == nullid:
+        if node == self.nullid:
             return b"", {}
 
         # ``rawtext`` is the text as stored inside the revlog. Might be the
@@ -2261,11 +2268,14 @@
         - rawtext is optional (can be None); if not set, cachedelta must be set.
           if both are set, they must correspond to each other.
         """
-        if node == nullid:
+        if node == self.nullid:
             raise error.RevlogError(
                 _(b"%s: attempt to add null revision") % self.indexfile
             )
-        if node == wdirid or node in wdirfilenodeids:
+        if (
+            node == self.nodeconstants.wdirid
+            or node in self.nodeconstants.wdirfilenodeids
+        ):
             raise error.RevlogError(
                 _(b"%s: attempt to add wdir revision") % self.indexfile
             )
diff --git a/mercurial/revset.py b/mercurial/revset.py
--- a/mercurial/revset.py
+++ b/mercurial/revset.py
@@ -11,6 +11,11 @@
 
 from .i18n import _
 from .pycompat import getattr
+from .node import (
+    bin,
+    nullrev,
+    wdirrev,
+)
 from . import (
     dagop,
     destutil,
@@ -20,7 +25,6 @@
     grep as grepmod,
     hbisect,
     match as matchmod,
-    node,
     obsolete as obsmod,
     obsutil,
     pathutil,
@@ -55,7 +59,7 @@
 fullreposet = smartset.fullreposet
 
 # revisions not included in all(), but populated if specified
-_virtualrevs = (node.nullrev, node.wdirrev)
+_virtualrevs = (nullrev, wdirrev)
 
 # Constants for ordering requirement, used in getset():
 #
@@ -177,9 +181,9 @@
 def _makerangeset(repo, subset, m, n, order):
     if m == n:
         r = baseset([m])
-    elif n == node.wdirrev:
+    elif n == wdirrev:
         r = spanset(repo, m, len(repo)) + baseset([n])
-    elif m == node.wdirrev:
+    elif m == wdirrev:
         r = baseset([m]) + spanset(repo, repo.changelog.tiprev(), n - 1)
     elif m < n:
         r = spanset(repo, m, n + 1)
@@ -598,7 +602,7 @@
                 bms.add(repo[bmrev].rev())
     else:
         bms = {repo[r].rev() for r in repo._bookmarks.values()}
-    bms -= {node.nullrev}
+    bms -= {nullrev}
     return subset & bms
 
 
@@ -723,7 +727,6 @@
     cs = set()
     pr = repo.changelog.parentrevs
     minrev = parentset.min()
-    nullrev = node.nullrev
     for r in subset:
         if r <= minrev:
             continue
@@ -1404,7 +1407,7 @@
                     b'_matchfiles expected at most one revision'
                 )
             if value == b'':  # empty means working directory
-                rev = node.wdirrev
+                rev = wdirrev
             else:
                 rev = value
         elif prefix == b'd:':
@@ -1424,7 +1427,6 @@
     # This directly read the changelog data as creating changectx for all
     # revisions is quite expensive.
     getfiles = repo.changelog.readfiles
-    wdirrev = node.wdirrev
 
     def matches(x):
         if x == wdirrev:
@@ -1500,15 +1502,15 @@
         order = followorder
     inputset = getset(repo, fullreposet(repo), x, order=order)
     wdirparents = None
-    if node.wdirrev in inputset:
+    if wdirrev in inputset:
         # a bit slower, but not common so good enough for now
         wdirparents = [p.rev() for p in repo[None].parents()]
         inputset = set(inputset)
-        inputset.discard(node.wdirrev)
+        inputset.discard(wdirrev)
     heads = repo.changelog.headrevs(inputset)
     if wdirparents is not None:
         heads.difference_update(wdirparents)
-        heads.add(node.wdirrev)
+        heads.add(wdirrev)
     heads = baseset(heads)
     return subset & heads
 
@@ -1613,7 +1615,6 @@
     # i18n: "merge" is a keyword
     getargs(x, 0, 0, _(b"merge takes no arguments"))
     cl = repo.changelog
-    nullrev = node.nullrev
 
     def ismerge(r):
         try:
@@ -1709,7 +1710,7 @@
             if name not in ns.deprecated:
                 names.update(repo[n].rev() for n in ns.nodes(repo, name))
 
-    names -= {node.nullrev}
+    names -= {nullrev}
     return subset & names
 
 
@@ -1723,9 +1724,9 @@
     n = getstring(l[0], _(b"id requires a string"))
     if len(n) == 40:
         try:
-            rn = repo.changelog.rev(node.bin(n))
+            rn = repo.changelog.rev(bin(n))
         except error.WdirUnsupported:
-            rn = node.wdirrev
+            rn = wdirrev
         except (LookupError, TypeError):
             rn = None
     else:
@@ -1737,7 +1738,7 @@
         except LookupError:
             pass
         except error.WdirUnsupported:
-            rn = node.wdirrev
+            rn = wdirrev
 
     if rn is None:
         return baseset()
@@ -1884,7 +1885,7 @@
             ps.add(cl.parentrevs(r)[0])
         except error.WdirUnsupported:
             ps.add(repo[r].p1().rev())
-    ps -= {node.nullrev}
+    ps -= {nullrev}
     # XXX we should turn this into a baseset instead of a set, smartset may do
     # some optimizations from the fact this is a baseset.
     return subset & ps
@@ -1913,7 +1914,7 @@
             parents = repo[r].parents()
             if len(parents) == 2:
                 ps.add(parents[1])
-    ps -= {node.nullrev}
+    ps -= {nullrev}
     # XXX we should turn this into a baseset instead of a set, smartset may do
     # some optimizations from the fact this is a baseset.
     return subset & ps
@@ -1940,7 +1941,7 @@
                 up(parentrevs(r))
             except error.WdirUnsupported:
                 up(p.rev() for p in repo[r].parents())
-    ps -= {node.nullrev}
+    ps -= {nullrev}
     return subset & ps
 
 
@@ -2015,7 +2016,7 @@
         else:
             try:
                 parents = cl.parentrevs(r)
-                if parents[1] != node.nullrev:
+                if parents[1] != nullrev:
                     ps.add(parents[1])
             except error.WdirUnsupported:
                 parents = repo[r].parents()
@@ -2592,8 +2593,8 @@
     """Working directory. (EXPERIMENTAL)"""
     # i18n: "wdir" is a keyword
     getargs(x, 0, 0, _(b"wdir takes no arguments"))
-    if node.wdirrev in subset or isinstance(subset, fullreposet):
-        return baseset([node.wdirrev])
+    if wdirrev in subset or isinstance(subset, fullreposet):
+        return baseset([wdirrev])
     return baseset()
 
 
@@ -2663,7 +2664,7 @@
     if not s:
         return baseset()
     cl = repo.changelog
-    ls = [cl.rev(node.bin(r)) for r in s.split(b'\0')]
+    ls = [cl.rev(bin(r)) for r in s.split(b'\0')]
     s = subset
     return baseset([r for r in ls if r in s])
 
diff --git a/mercurial/revsetlang.py b/mercurial/revsetlang.py
--- a/mercurial/revsetlang.py
+++ b/mercurial/revsetlang.py
@@ -11,9 +11,9 @@
 
 from .i18n import _
 from .pycompat import getattr
+from .node import hex
 from . import (
     error,
-    node,
     parser,
     pycompat,
     smartset,
@@ -688,7 +688,7 @@
         parse(arg)  # make sure syntax errors are confined
         return b'(%s)' % arg
     elif c == b'n':
-        return _quote(node.hex(arg))
+        return _quote(hex(arg))
     elif c == b'b':
         try:
             return _quote(arg.branch())
@@ -708,7 +708,7 @@
     elif t == b's':
         return b"_list(%s)" % _quote(b"\0".join(s))
     elif t == b'n':
-        return b"_hexlist('%s')" % b"\0".join(node.hex(a) for a in s)
+        return b"_hexlist('%s')" % b"\0".join(hex(a) for a in s)
     elif t == b'b':
         try:
             return b"_list('%s')" % b"\0".join(a.branch() for a in s)
diff --git a/mercurial/rewriteutil.py b/mercurial/rewriteutil.py
--- a/mercurial/rewriteutil.py
+++ b/mercurial/rewriteutil.py
@@ -10,10 +10,13 @@
 import re
 
 from .i18n import _
+from .node import (
+    hex,
+    nullrev,
+)
 
 from . import (
     error,
-    node,
     obsolete,
     obsutil,
     revset,
@@ -30,7 +33,7 @@
 
     Make sure this function is called after taking the lock.
     """
-    if node.nullrev in revs:
+    if nullrev in revs:
         msg = _(b"cannot %s null changeset") % action
         hint = _(b"no changeset checked out")
         raise error.InputError(msg, hint=hint)
@@ -113,7 +116,7 @@
         if len(successors) == 1 and len(successors[0]) == 1:
             successor = successors[0][0]
             if successor is not None:
-                newhash = node.hex(successor)
+                newhash = hex(successor)
                 commitmsg = commitmsg.replace(h, newhash[: len(h)])
             else:
                 repo.ui.note(
diff --git a/mercurial/scmutil.py b/mercurial/scmutil.py
--- a/mercurial/scmutil.py
+++ b/mercurial/scmutil.py
@@ -19,10 +19,8 @@
 from .node import (
     bin,
     hex,
-    nullid,
     nullrev,
     short,
-    wdirid,
     wdirrev,
 )
 from .pycompat import getattr
@@ -454,7 +452,7 @@
     """Return binary node id for a given basectx"""
     node = ctx.node()
     if node is None:
-        return wdirid
+        return ctx.repo().nodeconstants.wdirid
     return node
 
 
@@ -1112,7 +1110,7 @@
                     if roots:
                         newnode = roots[0].node()
                     else:
-                        newnode = nullid
+                        newnode = repo.nullid
                 else:
                     newnode = newnodes[0]
                 moves[oldnode] = newnode
@@ -1510,7 +1508,7 @@
     oldctx = repo[b'.']
     ds = repo.dirstate
     copies = dict(ds.copies())
-    ds.setparents(newctx.node(), nullid)
+    ds.setparents(newctx.node(), repo.nullid)
     s = newctx.status(oldctx, match=match)
     for f in s.modified:
         if ds[f] == b'r':
diff --git a/mercurial/setdiscovery.py b/mercurial/setdiscovery.py
--- a/mercurial/setdiscovery.py
+++ b/mercurial/setdiscovery.py
@@ -46,10 +46,7 @@
 import random
 
 from .i18n import _
-from .node import (
-    nullid,
-    nullrev,
-)
+from .node import nullrev
 from . import (
     error,
     policy,
@@ -376,10 +373,10 @@
 
     srvheadhashes, yesno = fheads.result(), fknown.result()
 
-    if cl.tip() == nullid:
-        if srvheadhashes != [nullid]:
-            return [nullid], True, srvheadhashes
-        return [nullid], False, []
+    if cl.tip() == cl.nullid:
+        if srvheadhashes != [cl.nullid]:
+            return [cl.nullid], True, srvheadhashes
+        return [cl.nullid], False, []
 
     # start actual discovery (we note this before the next "if" for
     # compatibility reasons)
@@ -387,7 +384,7 @@
 
     knownsrvheads = []  # revnos of remote heads that are known locally
     for node in srvheadhashes:
-        if node == nullid:
+        if node == cl.nullid:
             continue
 
         try:
@@ -467,17 +464,17 @@
     missing = set(result) - set(knownsrvheads)
     ui.log(b'discovery', msg, len(result), len(missing), roundtrips, elapsed)
 
-    if not result and srvheadhashes != [nullid]:
+    if not result and srvheadhashes != [cl.nullid]:
         if abortwhenunrelated:
             raise error.Abort(_(b"repository is unrelated"))
         else:
             ui.warn(_(b"warning: repository is unrelated\n"))
         return (
-            {nullid},
+            {cl.nullid},
             True,
             srvheadhashes,
         )
 
-    anyincoming = srvheadhashes != [nullid]
+    anyincoming = srvheadhashes != [cl.nullid]
     result = {clnode(r) for r in result}
     return result, anyincoming, srvheadhashes
diff --git a/mercurial/shelve.py b/mercurial/shelve.py
--- a/mercurial/shelve.py
+++ b/mercurial/shelve.py
@@ -29,6 +29,11 @@
 
 from .i18n import _
 from .pycompat import open
+from .node import (
+    bin,
+    hex,
+    nullrev,
+)
 from . import (
     bookmarks,
     bundle2,
@@ -43,7 +48,6 @@
     mdiff,
     merge,
     mergestate as mergestatemod,
-    node as nodemod,
     patch,
     phases,
     pycompat,
@@ -196,11 +200,11 @@
     def _verifyandtransform(cls, d):
         """Some basic shelvestate syntactic verification and transformation"""
         try:
-            d[b'originalwctx'] = nodemod.bin(d[b'originalwctx'])
-            d[b'pendingctx'] = nodemod.bin(d[b'pendingctx'])
-            d[b'parents'] = [nodemod.bin(h) for h in d[b'parents'].split(b' ')]
+            d[b'originalwctx'] = bin(d[b'originalwctx'])
+            d[b'pendingctx'] = bin(d[b'pendingctx'])
+            d[b'parents'] = [bin(h) for h in d[b'parents'].split(b' ')]
             d[b'nodestoremove'] = [
-                nodemod.bin(h) for h in d[b'nodestoremove'].split(b' ')
+                bin(h) for h in d[b'nodestoremove'].split(b' ')
             ]
         except (ValueError, TypeError, KeyError) as err:
             raise error.CorruptedState(pycompat.bytestr(err))
@@ -296,14 +300,10 @@
     ):
         info = {
             b"name": name,
-            b"originalwctx": nodemod.hex(originalwctx.node()),
-            b"pendingctx": nodemod.hex(pendingctx.node()),
-            b"parents": b' '.join(
-                [nodemod.hex(p) for p in repo.dirstate.parents()]
-            ),
-            b"nodestoremove": b' '.join(
-                [nodemod.hex(n) for n in nodestoremove]
-            ),
+            b"originalwctx": hex(originalwctx.node()),
+            b"pendingctx": hex(pendingctx.node()),
+            b"parents": b' '.join([hex(p) for p in repo.dirstate.parents()]),
+            b"nodestoremove": b' '.join([hex(n) for n in nodestoremove]),
             b"branchtorestore": branchtorestore,
             b"keep": cls._keep if keep else cls._nokeep,
             b"activebook": activebook or cls._noactivebook,
@@ -401,7 +401,7 @@
     """return all mutable ancestors for ctx (included)
 
     Much faster than the revset ancestors(ctx) & draft()"""
-    seen = {nodemod.nullrev}
+    seen = {nullrev}
     visit = collections.deque()
     visit.append(ctx)
     while visit:
@@ -465,7 +465,7 @@
 
 
 def _shelvecreatedcommit(repo, node, name, match):
-    info = {b'node': nodemod.hex(node)}
+    info = {b'node': hex(node)}
     shelvedfile(repo, name, b'shelve').writeinfo(info)
     bases = list(mutableancestors(repo[node]))
     shelvedfile(repo, name, b'hg').writebundle(bases, node)
@@ -502,7 +502,7 @@
     parent = parents[0]
     origbranch = wctx.branch()
 
-    if parent.node() != nodemod.nullid:
+    if parent.rev() != nullrev:
         desc = b"changes to: %s" % parent.description().split(b'\n', 1)[0]
     else:
         desc = b'(changes in empty repository)'
@@ -817,7 +817,7 @@
         pendingctx = state.pendingctx
 
         with repo.dirstate.parentchange():
-            repo.setparents(state.pendingctx.node(), nodemod.nullid)
+            repo.setparents(state.pendingctx.node(), repo.nullid)
             repo.dirstate.write(repo.currenttransaction())
 
         targetphase = phases.internal
@@ -826,7 +826,7 @@
         overrides = {(b'phases', b'new-commit'): targetphase}
         with repo.ui.configoverride(overrides, b'unshelve'):
             with repo.dirstate.parentchange():
-                repo.setparents(state.parents[0], nodemod.nullid)
+                repo.setparents(state.parents[0], repo.nullid)
                 newnode, ispartialunshelve = _createunshelvectx(
                     ui, repo, shelvectx, basename, interactive, opts
                 )
@@ -902,7 +902,7 @@
         # We might not strip the unbundled changeset, so we should keep track of
         # the unshelve node in case we need to reuse it (eg: unshelve --keep)
         if node is None:
-            info = {b'node': nodemod.hex(shelvectx.node())}
+            info = {b'node': hex(shelvectx.node())}
             shelvedfile(repo, basename, b'shelve').writeinfo(info)
     else:
         shelvectx = repo[node]
@@ -1021,7 +1021,7 @@
             raise error.ConflictResolutionRequired(b'unshelve')
 
         with repo.dirstate.parentchange():
-            repo.setparents(tmpwctx.node(), nodemod.nullid)
+            repo.setparents(tmpwctx.node(), repo.nullid)
             newnode, ispartialunshelve = _createunshelvectx(
                 ui, repo, shelvectx, basename, interactive, opts
             )
diff --git a/mercurial/simplemerge.py b/mercurial/simplemerge.py
--- a/mercurial/simplemerge.py
+++ b/mercurial/simplemerge.py
@@ -19,10 +19,10 @@
 from __future__ import absolute_import
 
 from .i18n import _
+from .node import nullrev
 from . import (
     error,
     mdiff,
-    node as nodemod,
     pycompat,
     util,
 )
@@ -454,7 +454,7 @@
 def is_not_null(ctx):
     if not util.safehasattr(ctx, "node"):
         return False
-    return ctx.node() != nodemod.nullid
+    return ctx.rev() != nullrev
 
 
 def simplemerge(ui, localctx, basectx, otherctx, **opts):
diff --git a/mercurial/sparse.py b/mercurial/sparse.py
--- a/mercurial/sparse.py
+++ b/mercurial/sparse.py
@@ -10,10 +10,7 @@
 import os
 
 from .i18n import _
-from .node import (
-    hex,
-    nullid,
-)
+from .node import hex
 from . import (
     error,
     match as matchmod,
@@ -177,7 +174,7 @@
     revs = [
         repo.changelog.rev(node)
         for node in repo.dirstate.parents()
-        if node != nullid
+        if node != repo.nullid
     ]
 
     allincludes = set()
@@ -321,7 +318,7 @@
         revs = [
             repo.changelog.rev(node)
             for node in repo.dirstate.parents()
-            if node != nullid
+            if node != repo.nullid
         ]
 
     signature = configsignature(repo, includetemp=includetemp)
diff --git a/mercurial/sslutil.py b/mercurial/sslutil.py
--- a/mercurial/sslutil.py
+++ b/mercurial/sslutil.py
@@ -16,10 +16,10 @@
 
 from .i18n import _
 from .pycompat import getattr
+from .node import hex
 from . import (
     encoding,
     error,
-    node,
     pycompat,
     util,
 )
@@ -763,9 +763,9 @@
     # If a certificate fingerprint is pinned, use it and only it to
     # validate the remote cert.
     peerfingerprints = {
-        b'sha1': node.hex(hashutil.sha1(peercert).digest()),
-        b'sha256': node.hex(hashlib.sha256(peercert).digest()),
-        b'sha512': node.hex(hashlib.sha512(peercert).digest()),
+        b'sha1': hex(hashutil.sha1(peercert).digest()),
+        b'sha256': hex(hashlib.sha256(peercert).digest()),
+        b'sha512': hex(hashlib.sha512(peercert).digest()),
     }
 
     def fmtfingerprint(s):
diff --git a/mercurial/statichttprepo.py b/mercurial/statichttprepo.py
--- a/mercurial/statichttprepo.py
+++ b/mercurial/statichttprepo.py
@@ -12,6 +12,7 @@
 import errno
 
 from .i18n import _
+from .node import sha1nodeconstants
 from . import (
     branchmap,
     changelog,
@@ -194,6 +195,8 @@
             requirements, supportedrequirements
         )
         localrepo.ensurerequirementscompatible(ui, requirements)
+        self.nodeconstants = sha1nodeconstants
+        self.nullid = self.nodeconstants.nullid
 
         # setup store
         self.store = localrepo.makestore(requirements, self.path, vfsclass)
@@ -203,7 +206,7 @@
         self._filecache = {}
         self.requirements = requirements
 
-        rootmanifest = manifest.manifestrevlog(self.svfs)
+        rootmanifest = manifest.manifestrevlog(self.nodeconstants, self.svfs)
         self.manifestlog = manifest.manifestlog(
             self.svfs, self, rootmanifest, self.narrowmatch()
         )
diff --git a/mercurial/store.py b/mercurial/store.py
--- a/mercurial/store.py
+++ b/mercurial/store.py
@@ -14,11 +14,11 @@
 
 from .i18n import _
 from .pycompat import getattr
+from .node import hex
 from . import (
     changelog,
     error,
     manifest,
-    node,
     policy,
     pycompat,
     util,
@@ -273,7 +273,7 @@
 
 
 def _hashencode(path, dotencode):
-    digest = node.hex(hashutil.sha1(path).digest())
+    digest = hex(hashutil.sha1(path).digest())
     le = lowerencode(path[5:]).split(b'/')  # skips prefix 'data/' or 'meta/'
     parts = _auxencode(le, dotencode)
     basename = parts[-1]
@@ -433,7 +433,7 @@
         return changelog.changelog(self.vfs, trypending=trypending)
 
     def manifestlog(self, repo, storenarrowmatch):
-        rootstore = manifest.manifestrevlog(self.vfs)
+        rootstore = manifest.manifestrevlog(repo.nodeconstants, self.vfs)
         return manifest.manifestlog(self.vfs, repo, rootstore, storenarrowmatch)
 
     def datafiles(self, matcher=None):
diff --git a/mercurial/strip.py b/mercurial/strip.py
--- a/mercurial/strip.py
+++ b/mercurial/strip.py
@@ -9,7 +9,6 @@
     hg,
     lock as lockmod,
     mergestate as mergestatemod,
-    node as nodemod,
     pycompat,
     registrar,
     repair,
@@ -17,7 +16,6 @@
     util,
 )
 
-nullid = nodemod.nullid
 release = lockmod.release
 
 cmdtable = {}
@@ -40,7 +38,7 @@
 
     if (
         util.safehasattr(repo, b'mq')
-        and p2 != nullid
+        and p2 != repo.nullid
         and p2 in [x.node for x in repo.mq.applied]
     ):
         unode = p2
@@ -214,7 +212,7 @@
         # if one of the wdir parent is stripped we'll need
         # to update away to an earlier revision
         update = any(
-            p != nullid and cl.rev(p) in strippedrevs
+            p != repo.nullid and cl.rev(p) in strippedrevs
             for p in repo.dirstate.parents()
         )
 
diff --git a/mercurial/subrepo.py b/mercurial/subrepo.py
--- a/mercurial/subrepo.py
+++ b/mercurial/subrepo.py
@@ -18,6 +18,11 @@
 import xml.dom.minidom
 
 from .i18n import _
+from .node import (
+    bin,
+    hex,
+    short,
+)
 from . import (
     cmdutil,
     encoding,
@@ -26,7 +31,6 @@
     logcmdutil,
     match as matchmod,
     merge as merge,
-    node,
     pathutil,
     phases,
     pycompat,
@@ -61,7 +65,7 @@
 
 def _getstorehashcachename(remotepath):
     '''get a unique filename for the store hash cache of a remote repository'''
-    return node.hex(hashutil.sha1(_expandedabspath(remotepath)).digest())[0:12]
+    return hex(hashutil.sha1(_expandedabspath(remotepath)).digest())[0:12]
 
 
 class SubrepoAbort(error.Abort):
@@ -512,7 +516,7 @@
         yield b'# %s\n' % _expandedabspath(remotepath)
         vfs = self._repo.vfs
         for relname in filelist:
-            filehash = node.hex(hashutil.sha1(vfs.tryread(relname)).digest())
+            filehash = hex(hashutil.sha1(vfs.tryread(relname)).digest())
             yield b'%s = %s\n' % (relname, filehash)
 
     @propertycache
@@ -606,11 +610,11 @@
     @annotatesubrepoerror
     def diff(self, ui, diffopts, node2, match, prefix, **opts):
         try:
-            node1 = node.bin(self._state[1])
+            node1 = bin(self._state[1])
             # We currently expect node2 to come from substate and be
             # in hex format
             if node2 is not None:
-                node2 = node.bin(node2)
+                node2 = bin(node2)
             logcmdutil.diffordiffstat(
                 ui,
                 self._repo,
@@ -674,7 +678,7 @@
         n = self._repo.commit(text, user, date)
         if not n:
             return self._repo[b'.'].hex()  # different version checked out
-        return node.hex(n)
+        return hex(n)
 
     @annotatesubrepoerror
     def phase(self, state):
@@ -685,7 +689,7 @@
         # we can't fully delete the repository as it may contain
         # local-only history
         self.ui.note(_(b'removing subrepo %s\n') % subrelpath(self))
-        hg.clean(self._repo, node.nullid, False)
+        hg.clean(self._repo, self._repo.nullid, False)
 
     def _get(self, state):
         source, revision, kind = state
@@ -1024,7 +1028,7 @@
                 # explicit warning.
                 msg = _(b"subrepo '%s' is hidden in revision %s") % (
                     self._relpath,
-                    node.short(self._ctx.node()),
+                    short(self._ctx.node()),
                 )
 
                 if onpush:
@@ -1037,7 +1041,7 @@
             # don't treat this as an error for `hg verify`.
             msg = _(b"subrepo '%s' not found in revision %s") % (
                 self._relpath,
-                node.short(self._ctx.node()),
+                short(self._ctx.node()),
             )
 
             if onpush:
diff --git a/mercurial/tagmerge.py b/mercurial/tagmerge.py
--- a/mercurial/tagmerge.py
+++ b/mercurial/tagmerge.py
@@ -74,17 +74,11 @@
 from __future__ import absolute_import
 
 from .i18n import _
-from .node import (
-    hex,
-    nullid,
-)
 from . import (
     tags as tagsmod,
     util,
 )
 
-hexnullid = hex(nullid)
-
 
 def readtagsformerge(ui, repo, lines, fn=b'', keeplinenums=False):
     '''read the .hgtags file into a structure that is suitable for merging
@@ -246,8 +240,8 @@
         pnlosttagset = basetagset - pntagset
         for t in pnlosttagset:
             pntags[t] = basetags[t]
-            if pntags[t][-1][0] != hexnullid:
-                pntags[t].append([hexnullid, None])
+            if pntags[t][-1][0] != repo.nodeconstants.nullhex:
+                pntags[t].append([repo.nodeconstants.nullhex, None])
 
     conflictedtags = []  # for reporting purposes
     mergedtags = util.sortdict(p1tags)
diff --git a/mercurial/tags.py b/mercurial/tags.py
--- a/mercurial/tags.py
+++ b/mercurial/tags.py
@@ -18,7 +18,6 @@
 from .node import (
     bin,
     hex,
-    nullid,
     nullrev,
     short,
 )
@@ -96,12 +95,12 @@
     return fnodes
 
 
-def _nulltonone(value):
+def _nulltonone(repo, value):
     """convert nullid to None
 
     For tag value, nullid means "deleted". This small utility function helps
     translating that to None."""
-    if value == nullid:
+    if value == repo.nullid:
         return None
     return value
 
@@ -123,14 +122,14 @@
     # list of (tag, old, new): None means missing
     entries = []
     for tag, (new, __) in newtags.items():
-        new = _nulltonone(new)
+        new = _nulltonone(repo, new)
         old, __ = oldtags.pop(tag, (None, None))
-        old = _nulltonone(old)
+        old = _nulltonone(repo, old)
         if old != new:
             entries.append((tag, old, new))
     # handle deleted tags
     for tag, (old, __) in oldtags.items():
-        old = _nulltonone(old)
+        old = _nulltonone(repo, old)
         if old is not None:
             entries.append((tag, old, None))
     entries.sort()
@@ -452,7 +451,7 @@
     repoheads = repo.heads()
     # Case 2 (uncommon): empty repo; get out quickly and don't bother
     # writing an empty cache.
-    if repoheads == [nullid]:
+    if repoheads == [repo.nullid]:
         return ([], {}, valid, {}, False)
 
     # Case 3 (uncommon): cache file missing or empty.
@@ -496,7 +495,7 @@
     cachefnode = {}
     for node in nodes:
         fnode = fnodescache.getfnode(node)
-        if fnode != nullid:
+        if fnode != repo.nullid:
             cachefnode[node] = fnode
 
     fnodescache.write()
@@ -618,7 +617,7 @@
                 m = name
 
             if repo._tagscache.tagtypes and name in repo._tagscache.tagtypes:
-                old = repo.tags().get(name, nullid)
+                old = repo.tags().get(name, repo.nullid)
                 fp.write(b'%s %s\n' % (hex(old), m))
             fp.write(b'%s %s\n' % (hex(node), m))
         fp.close()
@@ -746,8 +745,8 @@
         If an .hgtags does not exist at the specified revision, nullid is
         returned.
         """
-        if node == nullid:
-            return nullid
+        if node == self._repo.nullid:
+            return node
 
         ctx = self._repo[node]
         rev = ctx.rev()
@@ -799,7 +798,7 @@
                 fnode = ctx.filenode(b'.hgtags')
             except error.LookupError:
                 # No .hgtags file on this revision.
-                fnode = nullid
+                fnode = self._repo.nullid
 
         self._writeentry(offset, properprefix, fnode)
         return fnode
diff --git a/mercurial/templatefilters.py b/mercurial/templatefilters.py
--- a/mercurial/templatefilters.py
+++ b/mercurial/templatefilters.py
@@ -12,10 +12,10 @@
 import time
 
 from .i18n import _
+from .node import hex
 from . import (
     encoding,
     error,
-    node,
     pycompat,
     registrar,
     smartset,
@@ -280,7 +280,7 @@
     """Any text. Convert a binary Mercurial node identifier into
     its long hexadecimal representation.
     """
-    return node.hex(text)
+    return hex(text)
 
 
 @templatefilter(b'hgdate', intype=templateutil.date)
diff --git a/mercurial/templatefuncs.py b/mercurial/templatefuncs.py
--- a/mercurial/templatefuncs.py
+++ b/mercurial/templatefuncs.py
@@ -10,10 +10,7 @@
 import re
 
 from .i18n import _
-from .node import (
-    bin,
-    wdirid,
-)
+from .node import bin
 from . import (
     color,
     dagop,
@@ -778,7 +775,7 @@
         try:
             node = scmutil.resolvehexnodeidprefix(repo, hexnode)
         except error.WdirUnsupported:
-            node = wdirid
+            node = repo.nodeconstants.wdirid
         except error.LookupError:
             return hexnode
         if not node:
diff --git a/mercurial/templatekw.py b/mercurial/templatekw.py
--- a/mercurial/templatekw.py
+++ b/mercurial/templatekw.py
@@ -10,8 +10,6 @@
 from .i18n import _
 from .node import (
     hex,
-    nullid,
-    wdirid,
     wdirrev,
 )
 
@@ -412,7 +410,7 @@
 
 def getgraphnodecurrent(repo, ctx, cache):
     wpnodes = repo.dirstate.parents()
-    if wpnodes[1] == nullid:
+    if wpnodes[1] == repo.nullid:
         wpnodes = wpnodes[:1]
     if ctx.node() in wpnodes:
         return b'@'
@@ -525,11 +523,12 @@
     ctx = context.resource(mapping, b'ctx')
     mnode = ctx.manifestnode()
     if mnode is None:
-        mnode = wdirid
+        mnode = repo.nodeconstants.wdirid
         mrev = wdirrev
+        mhex = repo.nodeconstants.wdirhex
     else:
         mrev = repo.manifestlog.rev(mnode)
-    mhex = hex(mnode)
+        mhex = hex(mnode)
     mapping = context.overlaymap(mapping, {b'rev': mrev, b'node': mhex})
     f = context.process(b'manifest', mapping)
     return templateutil.hybriditem(
diff --git a/mercurial/testing/storage.py b/mercurial/testing/storage.py
--- a/mercurial/testing/storage.py
+++ b/mercurial/testing/storage.py
@@ -11,7 +11,6 @@
 
 from ..node import (
     hex,
-    nullid,
     nullrev,
 )
 from ..pycompat import getattr
@@ -51,7 +50,7 @@
         self.assertFalse(f.hasnode(None))
         self.assertFalse(f.hasnode(0))
         self.assertFalse(f.hasnode(nullrev))
-        self.assertFalse(f.hasnode(nullid))
+        self.assertFalse(f.hasnode(f.nullid))
         self.assertFalse(f.hasnode(b'0'))
         self.assertFalse(f.hasnode(b'a' * 20))
 
@@ -64,8 +63,8 @@
 
         self.assertEqual(list(f.revs(start=20)), [])
 
-        # parents() and parentrevs() work with nullid/nullrev.
-        self.assertEqual(f.parents(nullid), (nullid, nullid))
+        # parents() and parentrevs() work with f.nullid/nullrev.
+        self.assertEqual(f.parents(f.nullid), (f.nullid, f.nullid))
         self.assertEqual(f.parentrevs(nullrev), (nullrev, nullrev))
 
         with self.assertRaises(error.LookupError):
@@ -78,9 +77,9 @@
             with self.assertRaises(IndexError):
                 f.parentrevs(i)
 
-        # nullid/nullrev lookup always works.
-        self.assertEqual(f.rev(nullid), nullrev)
-        self.assertEqual(f.node(nullrev), nullid)
+        # f.nullid/nullrev lookup always works.
+        self.assertEqual(f.rev(f.nullid), nullrev)
+        self.assertEqual(f.node(nullrev), f.nullid)
 
         with self.assertRaises(error.LookupError):
             f.rev(b'\x01' * 20)
@@ -92,16 +91,16 @@
             with self.assertRaises(IndexError):
                 f.node(i)
 
-        self.assertEqual(f.lookup(nullid), nullid)
-        self.assertEqual(f.lookup(nullrev), nullid)
-        self.assertEqual(f.lookup(hex(nullid)), nullid)
-        self.assertEqual(f.lookup(b'%d' % nullrev), nullid)
+        self.assertEqual(f.lookup(f.nullid), f.nullid)
+        self.assertEqual(f.lookup(nullrev), f.nullid)
+        self.assertEqual(f.lookup(hex(f.nullid)), f.nullid)
+        self.assertEqual(f.lookup(b'%d' % nullrev), f.nullid)
 
         with self.assertRaises(error.LookupError):
             f.lookup(b'badvalue')
 
         with self.assertRaises(error.LookupError):
-            f.lookup(hex(nullid)[0:12])
+            f.lookup(hex(f.nullid)[0:12])
 
         with self.assertRaises(error.LookupError):
             f.lookup(b'-2')
@@ -140,19 +139,19 @@
             with self.assertRaises(IndexError):
                 f.iscensored(i)
 
-        self.assertEqual(list(f.commonancestorsheads(nullid, nullid)), [])
+        self.assertEqual(list(f.commonancestorsheads(f.nullid, f.nullid)), [])
 
         with self.assertRaises(ValueError):
             self.assertEqual(list(f.descendants([])), [])
 
         self.assertEqual(list(f.descendants([nullrev])), [])
 
-        self.assertEqual(f.heads(), [nullid])
-        self.assertEqual(f.heads(nullid), [nullid])
-        self.assertEqual(f.heads(None, [nullid]), [nullid])
-        self.assertEqual(f.heads(nullid, [nullid]), [nullid])
+        self.assertEqual(f.heads(), [f.nullid])
+        self.assertEqual(f.heads(f.nullid), [f.nullid])
+        self.assertEqual(f.heads(None, [f.nullid]), [f.nullid])
+        self.assertEqual(f.heads(f.nullid, [f.nullid]), [f.nullid])
 
-        self.assertEqual(f.children(nullid), [])
+        self.assertEqual(f.children(f.nullid), [])
 
         with self.assertRaises(error.LookupError):
             f.children(b'\x01' * 20)
@@ -160,7 +159,7 @@
     def testsinglerevision(self):
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
-            node = f.add(b'initial', None, tr, 0, nullid, nullid)
+            node = f.add(b'initial', None, tr, 0, f.nullid, f.nullid)
 
         self.assertEqual(len(f), 1)
         self.assertEqual(list(f), [0])
@@ -174,7 +173,7 @@
         self.assertTrue(f.hasnode(node))
         self.assertFalse(f.hasnode(hex(node)))
         self.assertFalse(f.hasnode(nullrev))
-        self.assertFalse(f.hasnode(nullid))
+        self.assertFalse(f.hasnode(f.nullid))
         self.assertFalse(f.hasnode(node[0:12]))
         self.assertFalse(f.hasnode(hex(node)[0:20]))
 
@@ -188,7 +187,7 @@
         self.assertEqual(list(f.revs(1, 0)), [1, 0])
         self.assertEqual(list(f.revs(2, 0)), [2, 1, 0])
 
-        self.assertEqual(f.parents(node), (nullid, nullid))
+        self.assertEqual(f.parents(node), (f.nullid, f.nullid))
         self.assertEqual(f.parentrevs(0), (nullrev, nullrev))
 
         with self.assertRaises(error.LookupError):
@@ -209,7 +208,7 @@
 
         self.assertEqual(f.lookup(node), node)
         self.assertEqual(f.lookup(0), node)
-        self.assertEqual(f.lookup(-1), nullid)
+        self.assertEqual(f.lookup(-1), f.nullid)
         self.assertEqual(f.lookup(b'0'), node)
         self.assertEqual(f.lookup(hex(node)), node)
 
@@ -256,9 +255,9 @@
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
-            node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
-            node1 = f.add(fulltext1, None, tr, 1, node0, nullid)
-            node2 = f.add(fulltext2, None, tr, 3, node1, nullid)
+            node0 = f.add(fulltext0, None, tr, 0, f.nullid, f.nullid)
+            node1 = f.add(fulltext1, None, tr, 1, node0, f.nullid)
+            node2 = f.add(fulltext2, None, tr, 3, node1, f.nullid)
 
         self.assertEqual(len(f), 3)
         self.assertEqual(list(f), [0, 1, 2])
@@ -284,9 +283,9 @@
         # TODO this is wrong
         self.assertEqual(list(f.revs(3, 2)), [3, 2])
 
-        self.assertEqual(f.parents(node0), (nullid, nullid))
-        self.assertEqual(f.parents(node1), (node0, nullid))
-        self.assertEqual(f.parents(node2), (node1, nullid))
+        self.assertEqual(f.parents(node0), (f.nullid, f.nullid))
+        self.assertEqual(f.parents(node1), (node0, f.nullid))
+        self.assertEqual(f.parents(node2), (node1, f.nullid))
 
         self.assertEqual(f.parentrevs(0), (nullrev, nullrev))
         self.assertEqual(f.parentrevs(1), (0, nullrev))
@@ -330,7 +329,7 @@
         with self.assertRaises(IndexError):
             f.iscensored(3)
 
-        self.assertEqual(f.commonancestorsheads(node1, nullid), [])
+        self.assertEqual(f.commonancestorsheads(node1, f.nullid), [])
         self.assertEqual(f.commonancestorsheads(node1, node0), [node0])
         self.assertEqual(f.commonancestorsheads(node1, node1), [node1])
         self.assertEqual(f.commonancestorsheads(node0, node1), [node0])
@@ -364,12 +363,12 @@
         f = self._makefilefn()
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(b'0', None, tr, 0, nullid, nullid)
-            node1 = f.add(b'1', None, tr, 1, node0, nullid)
-            node2 = f.add(b'2', None, tr, 2, node1, nullid)
-            node3 = f.add(b'3', None, tr, 3, node0, nullid)
-            node4 = f.add(b'4', None, tr, 4, node3, nullid)
-            node5 = f.add(b'5', None, tr, 5, node0, nullid)
+            node0 = f.add(b'0', None, tr, 0, f.nullid, f.nullid)
+            node1 = f.add(b'1', None, tr, 1, node0, f.nullid)
+            node2 = f.add(b'2', None, tr, 2, node1, f.nullid)
+            node3 = f.add(b'3', None, tr, 3, node0, f.nullid)
+            node4 = f.add(b'4', None, tr, 4, node3, f.nullid)
+            node5 = f.add(b'5', None, tr, 5, node0, f.nullid)
 
         self.assertEqual(len(f), 6)
 
@@ -427,24 +426,24 @@
             with self.assertRaises(IndexError):
                 f.size(i)
 
-        self.assertEqual(f.revision(nullid), b'')
-        self.assertEqual(f.rawdata(nullid), b'')
+        self.assertEqual(f.revision(f.nullid), b'')
+        self.assertEqual(f.rawdata(f.nullid), b'')
 
         with self.assertRaises(error.LookupError):
             f.revision(b'\x01' * 20)
 
-        self.assertEqual(f.read(nullid), b'')
+        self.assertEqual(f.read(f.nullid), b'')
 
         with self.assertRaises(error.LookupError):
             f.read(b'\x01' * 20)
 
-        self.assertFalse(f.renamed(nullid))
+        self.assertFalse(f.renamed(f.nullid))
 
         with self.assertRaises(error.LookupError):
             f.read(b'\x01' * 20)
 
-        self.assertTrue(f.cmp(nullid, b''))
-        self.assertTrue(f.cmp(nullid, b'foo'))
+        self.assertTrue(f.cmp(f.nullid, b''))
+        self.assertTrue(f.cmp(f.nullid, b'foo'))
 
         with self.assertRaises(error.LookupError):
             f.cmp(b'\x01' * 20, b'irrelevant')
@@ -455,7 +454,7 @@
             next(gen)
 
         # Emitting null node yields nothing.
-        gen = f.emitrevisions([nullid])
+        gen = f.emitrevisions([f.nullid])
         with self.assertRaises(StopIteration):
             next(gen)
 
@@ -468,7 +467,7 @@
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
-            node = f.add(fulltext, None, tr, 0, nullid, nullid)
+            node = f.add(fulltext, None, tr, 0, f.nullid, f.nullid)
 
         self.assertEqual(f.storageinfo(), {})
         self.assertEqual(
@@ -496,10 +495,10 @@
         rev = next(gen)
 
         self.assertEqual(rev.node, node)
-        self.assertEqual(rev.p1node, nullid)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p1node, f.nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertIsNone(rev.linknode)
-        self.assertEqual(rev.basenode, nullid)
+        self.assertEqual(rev.basenode, f.nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
         self.assertIsNone(rev.delta)
@@ -512,10 +511,10 @@
         rev = next(gen)
 
         self.assertEqual(rev.node, node)
-        self.assertEqual(rev.p1node, nullid)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p1node, f.nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertIsNone(rev.linknode)
-        self.assertEqual(rev.basenode, nullid)
+        self.assertEqual(rev.basenode, f.nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertEqual(rev.revision, fulltext)
         self.assertIsNone(rev.delta)
@@ -534,9 +533,9 @@
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
-            node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
-            node1 = f.add(fulltext1, None, tr, 1, node0, nullid)
-            node2 = f.add(fulltext2, None, tr, 3, node1, nullid)
+            node0 = f.add(fulltext0, None, tr, 0, f.nullid, f.nullid)
+            node1 = f.add(fulltext1, None, tr, 1, node0, f.nullid)
+            node2 = f.add(fulltext2, None, tr, 3, node1, f.nullid)
 
         self.assertEqual(f.storageinfo(), {})
         self.assertEqual(
@@ -596,10 +595,10 @@
         rev = next(gen)
 
         self.assertEqual(rev.node, node0)
-        self.assertEqual(rev.p1node, nullid)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p1node, f.nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertIsNone(rev.linknode)
-        self.assertEqual(rev.basenode, nullid)
+        self.assertEqual(rev.basenode, f.nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertEqual(rev.revision, fulltext0)
         self.assertIsNone(rev.delta)
@@ -608,7 +607,7 @@
 
         self.assertEqual(rev.node, node1)
         self.assertEqual(rev.p1node, node0)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertIsNone(rev.linknode)
         self.assertEqual(rev.basenode, node0)
         self.assertIsNone(rev.baserevisionsize)
@@ -622,7 +621,7 @@
 
         self.assertEqual(rev.node, node2)
         self.assertEqual(rev.p1node, node1)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertIsNone(rev.linknode)
         self.assertEqual(rev.basenode, node1)
         self.assertIsNone(rev.baserevisionsize)
@@ -641,10 +640,10 @@
         rev = next(gen)
 
         self.assertEqual(rev.node, node0)
-        self.assertEqual(rev.p1node, nullid)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p1node, f.nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertIsNone(rev.linknode)
-        self.assertEqual(rev.basenode, nullid)
+        self.assertEqual(rev.basenode, f.nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertEqual(rev.revision, fulltext0)
         self.assertIsNone(rev.delta)
@@ -653,7 +652,7 @@
 
         self.assertEqual(rev.node, node1)
         self.assertEqual(rev.p1node, node0)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertIsNone(rev.linknode)
         self.assertEqual(rev.basenode, node0)
         self.assertIsNone(rev.baserevisionsize)
@@ -667,7 +666,7 @@
 
         self.assertEqual(rev.node, node2)
         self.assertEqual(rev.p1node, node1)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertIsNone(rev.linknode)
         self.assertEqual(rev.basenode, node1)
         self.assertIsNone(rev.baserevisionsize)
@@ -700,16 +699,16 @@
         rev = next(gen)
         self.assertEqual(rev.node, node2)
         self.assertEqual(rev.p1node, node1)
-        self.assertEqual(rev.p2node, nullid)
-        self.assertEqual(rev.basenode, nullid)
+        self.assertEqual(rev.p2node, f.nullid)
+        self.assertEqual(rev.basenode, f.nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertEqual(rev.revision, fulltext2)
         self.assertIsNone(rev.delta)
 
         rev = next(gen)
         self.assertEqual(rev.node, node0)
-        self.assertEqual(rev.p1node, nullid)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p1node, f.nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         # Delta behavior is storage dependent, so we can't easily test it.
 
         with self.assertRaises(StopIteration):
@@ -722,8 +721,8 @@
         rev = next(gen)
         self.assertEqual(rev.node, node1)
         self.assertEqual(rev.p1node, node0)
-        self.assertEqual(rev.p2node, nullid)
-        self.assertEqual(rev.basenode, nullid)
+        self.assertEqual(rev.p2node, f.nullid)
+        self.assertEqual(rev.basenode, f.nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertEqual(rev.revision, fulltext1)
         self.assertIsNone(rev.delta)
@@ -731,7 +730,7 @@
         rev = next(gen)
         self.assertEqual(rev.node, node2)
         self.assertEqual(rev.p1node, node1)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertEqual(rev.basenode, node1)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
@@ -751,7 +750,7 @@
         rev = next(gen)
         self.assertEqual(rev.node, node1)
         self.assertEqual(rev.p1node, node0)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertEqual(rev.basenode, node0)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
@@ -768,9 +767,9 @@
 
         rev = next(gen)
         self.assertEqual(rev.node, node0)
-        self.assertEqual(rev.p1node, nullid)
-        self.assertEqual(rev.p2node, nullid)
-        self.assertEqual(rev.basenode, nullid)
+        self.assertEqual(rev.p1node, f.nullid)
+        self.assertEqual(rev.p2node, f.nullid)
+        self.assertEqual(rev.basenode, f.nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
         self.assertEqual(
@@ -789,9 +788,9 @@
 
         rev = next(gen)
         self.assertEqual(rev.node, node0)
-        self.assertEqual(rev.p1node, nullid)
-        self.assertEqual(rev.p2node, nullid)
-        self.assertEqual(rev.basenode, nullid)
+        self.assertEqual(rev.p1node, f.nullid)
+        self.assertEqual(rev.p2node, f.nullid)
+        self.assertEqual(rev.basenode, f.nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
         self.assertEqual(
@@ -802,7 +801,7 @@
         rev = next(gen)
         self.assertEqual(rev.node, node2)
         self.assertEqual(rev.p1node, node1)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertEqual(rev.basenode, node0)
 
         with self.assertRaises(StopIteration):
@@ -841,11 +840,11 @@
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
-            node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
-            node1 = f.add(fulltext1, meta1, tr, 1, node0, nullid)
-            node2 = f.add(fulltext2, meta2, tr, 2, nullid, nullid)
+            node0 = f.add(fulltext0, None, tr, 0, f.nullid, f.nullid)
+            node1 = f.add(fulltext1, meta1, tr, 1, node0, f.nullid)
+            node2 = f.add(fulltext2, meta2, tr, 2, f.nullid, f.nullid)
 
-        # Metadata header isn't recognized when parent isn't nullid.
+        # Metadata header isn't recognized when parent isn't f.nullid.
         self.assertEqual(f.size(1), len(stored1))
         self.assertEqual(f.size(2), len(fulltext2))
 
@@ -886,8 +885,8 @@
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
-            node0 = f.add(fulltext0, {}, tr, 0, nullid, nullid)
-            node1 = f.add(fulltext1, meta1, tr, 1, nullid, nullid)
+            node0 = f.add(fulltext0, {}, tr, 0, f.nullid, f.nullid)
+            node1 = f.add(fulltext1, meta1, tr, 1, f.nullid, f.nullid)
 
         # TODO this is buggy.
         self.assertEqual(f.size(0), len(fulltext0) + 4)
@@ -916,15 +915,15 @@
         fulltext1 = fulltext0 + b'bar\n'
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
+            node0 = f.add(fulltext0, None, tr, 0, f.nullid, f.nullid)
             node1 = b'\xaa' * 20
 
             self._addrawrevisionfn(
-                f, tr, node1, node0, nullid, 1, rawtext=fulltext1
+                f, tr, node1, node0, f.nullid, 1, rawtext=fulltext1
             )
 
         self.assertEqual(len(f), 2)
-        self.assertEqual(f.parents(node1), (node0, nullid))
+        self.assertEqual(f.parents(node1), (node0, f.nullid))
 
         # revision() raises since it performs hash verification.
         with self.assertRaises(error.StorageError):
@@ -951,11 +950,11 @@
         fulltext1 = fulltext0 + b'bar\n'
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
+            node0 = f.add(fulltext0, None, tr, 0, f.nullid, f.nullid)
             node1 = b'\xaa' * 20
 
             self._addrawrevisionfn(
-                f, tr, node1, node0, nullid, 1, rawtext=fulltext1
+                f, tr, node1, node0, f.nullid, 1, rawtext=fulltext1
             )
 
         with self.assertRaises(error.StorageError):
@@ -973,11 +972,11 @@
         fulltext1 = fulltext0 + b'bar\n'
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
+            node0 = f.add(fulltext0, None, tr, 0, f.nullid, f.nullid)
             node1 = b'\xaa' * 20
 
             self._addrawrevisionfn(
-                f, tr, node1, node0, nullid, 1, rawtext=fulltext1
+                f, tr, node1, node0, f.nullid, 1, rawtext=fulltext1
             )
 
         with self.assertRaises(error.StorageError):
@@ -994,22 +993,22 @@
         fulltext2 = fulltext1 + b'baz\n'
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
+            node0 = f.add(fulltext0, None, tr, 0, f.nullid, f.nullid)
             node1 = b'\xaa' * 20
 
             self._addrawrevisionfn(
-                f, tr, node1, node0, nullid, 1, rawtext=fulltext1
+                f, tr, node1, node0, f.nullid, 1, rawtext=fulltext1
             )
 
         with self.assertRaises(error.StorageError):
             f.read(node1)
 
-        node2 = storageutil.hashrevisionsha1(fulltext2, node1, nullid)
+        node2 = storageutil.hashrevisionsha1(fulltext2, node1, f.nullid)
 
         with self._maketransactionfn() as tr:
             delta = mdiff.textdiff(fulltext1, fulltext2)
             self._addrawrevisionfn(
-                f, tr, node2, node1, nullid, 2, delta=(1, delta)
+                f, tr, node2, node1, f.nullid, 2, delta=(1, delta)
             )
 
         self.assertEqual(len(f), 3)
@@ -1024,13 +1023,13 @@
         stored1 = storageutil.packmeta({b'censored': b'tombstone',}, b'')
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(b'foo', None, tr, 0, nullid, nullid)
+            node0 = f.add(b'foo', None, tr, 0, f.nullid, f.nullid)
 
             # The node value doesn't matter since we can't verify it.
             node1 = b'\xbb' * 20
 
             self._addrawrevisionfn(
-                f, tr, node1, node0, nullid, 1, stored1, censored=True
+                f, tr, node1, node0, f.nullid, 1, stored1, censored=True
             )
 
         self.assertTrue(f.iscensored(1))
@@ -1053,13 +1052,13 @@
         stored1 = storageutil.packmeta({b'censored': b'tombstone',}, b'')
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(b'foo', None, tr, 0, nullid, nullid)
+            node0 = f.add(b'foo', None, tr, 0, f.nullid, f.nullid)
 
             # The node value doesn't matter since we can't verify it.
             node1 = b'\xbb' * 20
 
             self._addrawrevisionfn(
-                f, tr, node1, node0, nullid, 1, stored1, censored=True
+                f, tr, node1, node0, f.nullid, 1, stored1, censored=True
             )
 
         with self.assertRaises(error.CensoredNodeError):
@@ -1078,10 +1077,10 @@
     def testaddnoop(self):
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
-            node0 = f.add(b'foo', None, tr, 0, nullid, nullid)
-            node1 = f.add(b'foo', None, tr, 0, nullid, nullid)
+            node0 = f.add(b'foo', None, tr, 0, f.nullid, f.nullid)
+            node1 = f.add(b'foo', None, tr, 0, f.nullid, f.nullid)
             # Varying by linkrev shouldn't impact hash.
-            node2 = f.add(b'foo', None, tr, 1, nullid, nullid)
+            node2 = f.add(b'foo', None, tr, 1, f.nullid, f.nullid)
 
         self.assertEqual(node1, node0)
         self.assertEqual(node2, node0)
@@ -1092,7 +1091,9 @@
         with self._maketransactionfn() as tr:
             # Adding a revision with bad node value fails.
             with self.assertRaises(error.StorageError):
-                f.addrevision(b'foo', tr, 0, nullid, nullid, node=b'\x01' * 20)
+                f.addrevision(
+                    b'foo', tr, 0, f.nullid, f.nullid, node=b'\x01' * 20
+                )
 
     def testaddrevisionunknownflag(self):
         f = self._makefilefn()
@@ -1103,7 +1104,7 @@
                     break
 
             with self.assertRaises(error.StorageError):
-                f.addrevision(b'foo', tr, 0, nullid, nullid, flags=flags)
+                f.addrevision(b'foo', tr, 0, f.nullid, f.nullid, flags=flags)
 
     def testaddgroupsimple(self):
         f = self._makefilefn()
@@ -1142,12 +1143,12 @@
         delta0 = mdiff.trivialdiffheader(len(fulltext0)) + fulltext0
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
+            node0 = f.add(fulltext0, None, tr, 0, f.nullid, f.nullid)
 
         f = self._makefilefn()
 
         deltas = [
-            (node0, nullid, nullid, nullid, nullid, delta0, 0),
+            (node0, f.nullid, f.nullid, f.nullid, f.nullid, delta0, 0),
         ]
 
         with self._maketransactionfn() as tr:
@@ -1195,14 +1196,16 @@
         nodes = []
         with self._maketransactionfn() as tr:
             for fulltext in fulltexts:
-                nodes.append(f.add(fulltext, None, tr, 0, nullid, nullid))
+                nodes.append(f.add(fulltext, None, tr, 0, f.nullid, f.nullid))
 
         f = self._makefilefn()
         deltas = []
         for i, fulltext in enumerate(fulltexts):
             delta = mdiff.trivialdiffheader(len(fulltext)) + fulltext
 
-            deltas.append((nodes[i], nullid, nullid, nullid, nullid, delta, 0))
+            deltas.append(
+                (nodes[i], f.nullid, f.nullid, f.nullid, f.nullid, delta, 0)
+            )
 
         with self._maketransactionfn() as tr:
             newnodes = []
@@ -1235,17 +1238,19 @@
         stored1 = storageutil.packmeta({b'censored': b'tombstone',}, b'')
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(b'foo\n' * 30, None, tr, 0, nullid, nullid)
+            node0 = f.add(b'foo\n' * 30, None, tr, 0, f.nullid, f.nullid)
 
             # The node value doesn't matter since we can't verify it.
             node1 = b'\xbb' * 20
 
             self._addrawrevisionfn(
-                f, tr, node1, node0, nullid, 1, stored1, censored=True
+                f, tr, node1, node0, f.nullid, 1, stored1, censored=True
             )
 
         delta = mdiff.textdiff(b'bar\n' * 30, (b'bar\n' * 30) + b'baz\n')
-        deltas = [(b'\xcc' * 20, node1, nullid, b'\x01' * 20, node1, delta, 0)]
+        deltas = [
+            (b'\xcc' * 20, node1, f.nullid, b'\x01' * 20, node1, delta, 0)
+        ]
 
         with self._maketransactionfn() as tr:
             with self.assertRaises(error.CensoredBaseError):
@@ -1255,9 +1260,9 @@
         f = self._makefilefn()
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(b'foo\n' * 30, None, tr, 0, nullid, nullid)
-            node1 = f.add(b'foo\n' * 31, None, tr, 1, node0, nullid)
-            node2 = f.add(b'foo\n' * 32, None, tr, 2, node1, nullid)
+            node0 = f.add(b'foo\n' * 30, None, tr, 0, f.nullid, f.nullid)
+            node1 = f.add(b'foo\n' * 31, None, tr, 1, node0, f.nullid)
+            node2 = f.add(b'foo\n' * 32, None, tr, 2, node1, f.nullid)
 
         with self._maketransactionfn() as tr:
             f.censorrevision(tr, node1)
@@ -1277,7 +1282,7 @@
 
         with self._maketransactionfn() as tr:
             for rev in range(10):
-                f.add(b'%d' % rev, None, tr, rev, nullid, nullid)
+                f.add(b'%d' % rev, None, tr, rev, f.nullid, f.nullid)
 
         for rev in range(10):
             self.assertEqual(f.getstrippoint(rev), (rev, set()))
@@ -1287,10 +1292,10 @@
         f = self._makefilefn()
 
         with self._maketransactionfn() as tr:
-            p1 = nullid
+            p1 = f.nullid
 
             for rev in range(10):
-                f.add(b'%d' % rev, None, tr, rev, p1, nullid)
+                f.add(b'%d' % rev, None, tr, rev, p1, f.nullid)
 
         for rev in range(10):
             self.assertEqual(f.getstrippoint(rev), (rev, set()))
@@ -1299,11 +1304,11 @@
         f = self._makefilefn()
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(b'0', None, tr, 0, nullid, nullid)
-            node1 = f.add(b'1', None, tr, 1, node0, nullid)
-            f.add(b'2', None, tr, 2, node1, nullid)
-            f.add(b'3', None, tr, 3, node0, nullid)
-            f.add(b'4', None, tr, 4, node0, nullid)
+            node0 = f.add(b'0', None, tr, 0, f.nullid, f.nullid)
+            node1 = f.add(b'1', None, tr, 1, node0, f.nullid)
+            f.add(b'2', None, tr, 2, node1, f.nullid)
+            f.add(b'3', None, tr, 3, node0, f.nullid)
+            f.add(b'4', None, tr, 4, node0, f.nullid)
 
         for rev in range(5):
             self.assertEqual(f.getstrippoint(rev), (rev, set()))
@@ -1312,9 +1317,9 @@
         f = self._makefilefn()
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(b'0', None, tr, 0, nullid, nullid)
-            f.add(b'1', None, tr, 10, node0, nullid)
-            f.add(b'2', None, tr, 5, node0, nullid)
+            node0 = f.add(b'0', None, tr, 0, f.nullid, f.nullid)
+            f.add(b'1', None, tr, 10, node0, f.nullid)
+            f.add(b'2', None, tr, 5, node0, f.nullid)
 
         self.assertEqual(f.getstrippoint(0), (0, set()))
         self.assertEqual(f.getstrippoint(1), (1, set()))
@@ -1341,9 +1346,9 @@
         f = self._makefilefn()
 
         with self._maketransactionfn() as tr:
-            p1 = nullid
+            p1 = f.nullid
             for rev in range(10):
-                p1 = f.add(b'%d' % rev, None, tr, rev, p1, nullid)
+                p1 = f.add(b'%d' % rev, None, tr, rev, p1, f.nullid)
 
         self.assertEqual(len(f), 10)
 
@@ -1356,9 +1361,9 @@
         f = self._makefilefn()
 
         with self._maketransactionfn() as tr:
-            f.add(b'0', None, tr, 0, nullid, nullid)
-            node1 = f.add(b'1', None, tr, 5, nullid, nullid)
-            node2 = f.add(b'2', None, tr, 10, nullid, nullid)
+            f.add(b'0', None, tr, 0, f.nullid, f.nullid)
+            node1 = f.add(b'1', None, tr, 5, f.nullid, f.nullid)
+            node2 = f.add(b'2', None, tr, 10, f.nullid, f.nullid)
 
         self.assertEqual(len(f), 3)
 
diff --git a/mercurial/thirdparty/selectors2.py b/mercurial/thirdparty/selectors2.py
--- a/mercurial/thirdparty/selectors2.py
+++ b/mercurial/thirdparty/selectors2.py
@@ -48,14 +48,16 @@
 __license__ = 'MIT'
 __url__ = 'https://www.github.com/SethMichaelLarson/selectors2'
 
-__all__ = ['EVENT_READ',
-           'EVENT_WRITE',
-           'SelectorKey',
-           'DefaultSelector',
-           'BaseSelector']
+__all__ = [
+    'EVENT_READ',
+    'EVENT_WRITE',
+    'SelectorKey',
+    'DefaultSelector',
+    'BaseSelector',
+]
 
-EVENT_READ = (1 << 0)
-EVENT_WRITE = (1 << 1)
+EVENT_READ = 1 << 0
+EVENT_WRITE = 1 << 1
 _DEFAULT_SELECTOR = None
 _SYSCALL_SENTINEL = object()  # Sentinel in case a system call returns None.
 _ERROR_TYPES = (OSError, IOError, socket.error)
@@ -114,6 +116,7 @@
     and kqueue()) depending on the platform. The 'DefaultSelector' class uses
     the most efficient implementation for the current platform.
     """
+
     def __init__(self):
         # Maps file descriptors to keys.
         self._fd_to_key = {}
@@ -149,8 +152,9 @@
         key = SelectorKey(fileobj, self._fileobj_lookup(fileobj), events, data)
 
         if key.fd in self._fd_to_key:
-            raise KeyError("{0!r} (FD {1}) is already registered"
-                           .format(fileobj, key.fd))
+            raise KeyError(
+                "{0!r} (FD {1}) is already registered".format(fileobj, key.fd)
+            )
 
         self._fd_to_key[key.fd] = key
         return key
@@ -236,8 +240,10 @@
 
 # Almost all platforms have select.select()
 if hasattr(select, "select"):
+
     class SelectSelector(BaseSelector):
         """ Select-based selector. """
+
         def __init__(self):
             super(SelectSelector, self).__init__()
             self._readers = set()
@@ -264,8 +270,9 @@
 
             timeout = None if timeout is None else max(timeout, 0.0)
             ready = []
-            r, w, _ = _syscall_wrapper(self._wrap_select, True, self._readers,
-                                       self._writers, timeout)
+            r, w, _ = _syscall_wrapper(
+                self._wrap_select, True, self._readers, self._writers, timeout
+            )
             r = set(r)
             w = set(w)
             for fd in r | w:
@@ -288,6 +295,7 @@
 
     # Jython has a different implementation of .fileno() for socket objects.
     if pycompat.isjython:
+
         class _JythonSelectorMapping(object):
             """ This is an implementation of _SelectorMapping that is built
             for use specifically with Jython, which does not provide a hashable
@@ -321,19 +329,24 @@
             def __init__(self):
                 super(JythonSelectSelector, self).__init__()
 
-                self._sockets = []  # Uses a list of tuples instead of dictionary.
+                self._sockets = (
+                    []
+                )  # Uses a list of tuples instead of dictionary.
                 self._map = _JythonSelectorMapping(self)
                 self._readers = []
                 self._writers = []
 
                 # Jython has a select.cpython_compatible_select function in older versions.
-                self._select_func = getattr(select, 'cpython_compatible_select', select.select)
+                self._select_func = getattr(
+                    select, 'cpython_compatible_select', select.select
+                )
 
             def register(self, fileobj, events, data=None):
                 for sock, _ in self._sockets:
                     if sock is fileobj:
-                        raise KeyError("{0!r} is already registered"
-                                       .format(fileobj, sock))
+                        raise KeyError(
+                            "{0!r} is already registered".format(fileobj, sock)
+                        )
 
                 key = SelectorKey(fileobj, -1, events, data)
                 self._sockets.append((fileobj, key))
@@ -364,12 +377,16 @@
                 return self._select_func(r, w, [], timeout)
 
         __all__.append('JythonSelectSelector')
-        SelectSelector = JythonSelectSelector  # Override so the wrong selector isn't used.
+        SelectSelector = (
+            JythonSelectSelector  # Override so the wrong selector isn't used.
+        )
 
 
 if hasattr(select, "poll"):
+
     class PollSelector(BaseSelector):
         """ Poll-based selector """
+
         def __init__(self):
             super(PollSelector, self).__init__()
             self._poll = select.poll()
@@ -422,8 +439,10 @@
     __all__.append('PollSelector')
 
 if hasattr(select, "epoll"):
+
     class EpollSelector(BaseSelector):
         """ Epoll-based selector """
+
         def __init__(self):
             super(EpollSelector, self).__init__()
             self._epoll = select.epoll()
@@ -468,9 +487,9 @@
             max_events = max(len(self._fd_to_key), 1)
 
             ready = []
-            fd_events = _syscall_wrapper(self._epoll.poll, True,
-                                         timeout=timeout,
-                                         maxevents=max_events)
+            fd_events = _syscall_wrapper(
+                self._epoll.poll, True, timeout=timeout, maxevents=max_events
+            )
             for fd, event_mask in fd_events:
                 events = 0
                 if event_mask & ~select.EPOLLIN:
@@ -491,6 +510,7 @@
 
 
 if hasattr(select, "devpoll"):
+
     class DevpollSelector(BaseSelector):
         """Solaris /dev/poll selector."""
 
@@ -554,8 +574,10 @@
 
 
 if hasattr(select, "kqueue"):
+
     class KqueueSelector(BaseSelector):
         """ Kqueue / Kevent-based selector """
+
         def __init__(self):
             super(KqueueSelector, self).__init__()
             self._kqueue = select.kqueue()
@@ -566,16 +588,16 @@
         def register(self, fileobj, events, data=None):
             key = super(KqueueSelector, self).register(fileobj, events, data)
             if events & EVENT_READ:
-                kevent = select.kevent(key.fd,
-                                       select.KQ_FILTER_READ,
-                                       select.KQ_EV_ADD)
+                kevent = select.kevent(
+                    key.fd, select.KQ_FILTER_READ, select.KQ_EV_ADD
+                )
 
                 _syscall_wrapper(self._kqueue.control, False, [kevent], 0, 0)
 
             if events & EVENT_WRITE:
-                kevent = select.kevent(key.fd,
-                                       select.KQ_FILTER_WRITE,
-                                       select.KQ_EV_ADD)
+                kevent = select.kevent(
+                    key.fd, select.KQ_FILTER_WRITE, select.KQ_EV_ADD
+                )
 
                 _syscall_wrapper(self._kqueue.control, False, [kevent], 0, 0)
 
@@ -584,19 +606,23 @@
         def unregister(self, fileobj):
             key = super(KqueueSelector, self).unregister(fileobj)
             if key.events & EVENT_READ:
-                kevent = select.kevent(key.fd,
-                                       select.KQ_FILTER_READ,
-                                       select.KQ_EV_DELETE)
+                kevent = select.kevent(
+                    key.fd, select.KQ_FILTER_READ, select.KQ_EV_DELETE
+                )
                 try:
-                    _syscall_wrapper(self._kqueue.control, False, [kevent], 0, 0)
+                    _syscall_wrapper(
+                        self._kqueue.control, False, [kevent], 0, 0
+                    )
                 except _ERROR_TYPES:
                     pass
             if key.events & EVENT_WRITE:
-                kevent = select.kevent(key.fd,
-                                       select.KQ_FILTER_WRITE,
-                                       select.KQ_EV_DELETE)
+                kevent = select.kevent(
+                    key.fd, select.KQ_FILTER_WRITE, select.KQ_EV_DELETE
+                )
                 try:
-                    _syscall_wrapper(self._kqueue.control, False, [kevent], 0, 0)
+                    _syscall_wrapper(
+                        self._kqueue.control, False, [kevent], 0, 0
+                    )
                 except _ERROR_TYPES:
                     pass
 
@@ -609,8 +635,9 @@
             max_events = len(self._fd_to_key) * 2
             ready_fds = {}
 
-            kevent_list = _syscall_wrapper(self._kqueue.control, True,
-                                           None, max_events, timeout)
+            kevent_list = _syscall_wrapper(
+                self._kqueue.control, True, None, max_events, timeout
+            )
 
             for kevent in kevent_list:
                 fd = kevent.ident
@@ -627,7 +654,10 @@
                         ready_fds[key.fd] = (key, events & key.events)
                     else:
                         old_events = ready_fds[key.fd][1]
-                        ready_fds[key.fd] = (key, (events | old_events) & key.events)
+                        ready_fds[key.fd] = (
+                            key,
+                            (events | old_events) & key.events,
+                        )
 
             return list(ready_fds.values())
 
@@ -659,11 +689,15 @@
 
 # Python 3.5 uses a more direct route to wrap system calls to increase speed.
 if sys.version_info >= (3, 5):
+
     def _syscall_wrapper(func, _, *args, **kwargs):
         """ This is the short-circuit version of the below logic
         because in Python 3.5+ all selectors restart system calls. """
         return func(*args, **kwargs)
+
+
 else:
+
     def _syscall_wrapper(func, recalc_timeout, *args, **kwargs):
         """ Wrapper function for syscalls that could fail due to EINTR.
         All functions should be retried if there is time left in the timeout
@@ -682,7 +716,8 @@
         args = list(args)
         if recalc_timeout and "timeout" not in kwargs:
             raise ValueError(
-                "Timeout must be in args or kwargs to be recalculated")
+                "Timeout must be in args or kwargs to be recalculated"
+            )
 
         result = _SYSCALL_SENTINEL
         while result is _SYSCALL_SENTINEL:
@@ -701,14 +736,17 @@
                     errcode = e.args[0]
 
                 # Also test for the Windows equivalent of EINTR.
-                is_interrupt = (errcode == errno.EINTR or (hasattr(errno, "WSAEINTR") and
-                                                           errcode == errno.WSAEINTR))
+                is_interrupt = errcode == errno.EINTR or (
+                    hasattr(errno, "WSAEINTR") and errcode == errno.WSAEINTR
+                )
 
                 if is_interrupt:
                     if expires is not None:
                         current_time = monotonic()
                         if current_time > expires:
-                            raise OSError(errno.ETIMEDOUT, 'Connection timed out')
+                            raise OSError(
+                                errno.ETIMEDOUT, 'Connection timed out'
+                            )
                         if recalc_timeout:
                             if "timeout" in kwargs:
                                 kwargs["timeout"] = expires - current_time
diff --git a/mercurial/treediscovery.py b/mercurial/treediscovery.py
--- a/mercurial/treediscovery.py
+++ b/mercurial/treediscovery.py
@@ -10,10 +10,7 @@
 import collections
 
 from .i18n import _
-from .node import (
-    nullid,
-    short,
-)
+from .node import short
 from . import (
     error,
     pycompat,
@@ -41,11 +38,11 @@
         with remote.commandexecutor() as e:
             heads = e.callcommand(b'heads', {}).result()
 
-    if repo.changelog.tip() == nullid:
-        base.add(nullid)
-        if heads != [nullid]:
-            return [nullid], [nullid], list(heads)
-        return [nullid], [], heads
+    if repo.changelog.tip() == repo.nullid:
+        base.add(repo.nullid)
+        if heads != [repo.nullid]:
+            return [repo.nullid], [repo.nullid], list(heads)
+        return [repo.nullid], [], heads
 
     # assume we're closer to the tip than the root
     # and start by examining the heads
@@ -81,7 +78,7 @@
                 continue
 
             repo.ui.debug(b"examining %s:%s\n" % (short(n[0]), short(n[1])))
-            if n[0] == nullid:  # found the end of the branch
+            if n[0] == repo.nullid:  # found the end of the branch
                 pass
             elif n in seenbranch:
                 repo.ui.debug(b"branch already found\n")
@@ -164,7 +161,7 @@
             raise error.RepoError(_(b"already have changeset ") + short(f[:4]))
 
     base = list(base)
-    if base == [nullid]:
+    if base == [repo.nullid]:
         if force:
             repo.ui.warn(_(b"warning: repository is unrelated\n"))
         else:
diff --git a/mercurial/unionrepo.py b/mercurial/unionrepo.py
--- a/mercurial/unionrepo.py
+++ b/mercurial/unionrepo.py
@@ -152,9 +152,9 @@
 
 
 class unionmanifest(unionrevlog, manifest.manifestrevlog):
-    def __init__(self, opener, opener2, linkmapper):
-        manifest.manifestrevlog.__init__(self, opener)
-        manifest2 = manifest.manifestrevlog(opener2)
+    def __init__(self, nodeconstants, opener, opener2, linkmapper):
+        manifest.manifestrevlog.__init__(self, nodeconstants, opener)
+        manifest2 = manifest.manifestrevlog(nodeconstants, opener2)
         unionrevlog.__init__(
             self, opener, self.indexfile, manifest2, linkmapper
         )
@@ -204,7 +204,10 @@
     @localrepo.unfilteredpropertycache
     def manifestlog(self):
         rootstore = unionmanifest(
-            self.svfs, self.repo2.svfs, self.unfiltered()._clrev
+            self.nodeconstants,
+            self.svfs,
+            self.repo2.svfs,
+            self.unfiltered()._clrev,
         )
         return manifest.manifestlog(
             self.svfs, self, rootstore, self.narrowmatch()
diff --git a/mercurial/upgrade.py b/mercurial/upgrade.py
--- a/mercurial/upgrade.py
+++ b/mercurial/upgrade.py
@@ -673,7 +673,9 @@
         return changelog.changelog(repo.svfs)
     elif path.endswith(b'00manifest.i'):
         mandir = path[: -len(b'00manifest.i')]
-        return manifest.manifestrevlog(repo.svfs, tree=mandir)
+        return manifest.manifestrevlog(
+            repo.nodeconstants, repo.svfs, tree=mandir
+        )
     else:
         # reverse of "/".join(("data", path + ".i"))
         return filelog.filelog(repo.svfs, path[5:-2])
diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -35,6 +35,7 @@
 import traceback
 import warnings
 
+from .node import hex
 from .thirdparty import attr
 from .pycompat import (
     delattr,
@@ -47,7 +48,6 @@
     encoding,
     error,
     i18n,
-    node as nodemod,
     policy,
     pycompat,
     urllibcompat,
@@ -254,7 +254,7 @@
     def __getitem__(self, key):
         if key not in DIGESTS:
             raise error.Abort(_(b'unknown digest type: %s') % k)
-        return nodemod.hex(self._hashes[key].digest())
+        return hex(self._hashes[key].digest())
 
     def __iter__(self):
         return iter(self._hashes)
diff --git a/mercurial/utils/storageutil.py b/mercurial/utils/storageutil.py
--- a/mercurial/utils/storageutil.py
+++ b/mercurial/utils/storageutil.py
@@ -13,8 +13,8 @@
 from ..i18n import _
 from ..node import (
     bin,
-    nullid,
     nullrev,
+    sha1nodeconstants,
 )
 from .. import (
     dagop,
@@ -25,7 +25,7 @@
 from ..interfaces import repository
 from ..utils import hashutil
 
-_nullhash = hashutil.sha1(nullid)
+_nullhash = hashutil.sha1(sha1nodeconstants.nullid)
 
 
 def hashrevisionsha1(text, p1, p2):
@@ -36,7 +36,7 @@
     content in the revision graph.
     """
     # As of now, if one of the parent node is null, p2 is null
-    if p2 == nullid:
+    if p2 == sha1nodeconstants.nullid:
         # deep copy of a hash is faster than creating one
         s = _nullhash.copy()
         s.update(p1)
@@ -106,7 +106,7 @@
     Returns ``False`` if the file has no copy metadata. Otherwise a
     2-tuple of the source filename and node.
     """
-    if store.parents(node)[0] != nullid:
+    if store.parents(node)[0] != sha1nodeconstants.nullid:
         return False
 
     meta = parsemeta(store.revision(node))[0]
diff --git a/mercurial/verify.py b/mercurial/verify.py
--- a/mercurial/verify.py
+++ b/mercurial/verify.py
@@ -10,10 +10,7 @@
 import os
 
 from .i18n import _
-from .node import (
-    nullid,
-    short,
-)
+from .node import short
 
 from . import (
     error,
@@ -156,13 +153,13 @@
 
         try:
             p1, p2 = obj.parents(node)
-            if p1 not in seen and p1 != nullid:
+            if p1 not in seen and p1 != self.repo.nullid:
                 self._err(
                     lr,
                     _(b"unknown parent 1 %s of %s") % (short(p1), short(node)),
                     f,
                 )
-            if p2 not in seen and p2 != nullid:
+            if p2 not in seen and p2 != self.repo.nullid:
                 self._err(
                     lr,
                     _(b"unknown parent 2 %s of %s") % (short(p2), short(node)),
@@ -264,7 +261,7 @@
 
             try:
                 changes = cl.read(n)
-                if changes[0] != nullid:
+                if changes[0] != self.repo.nullid:
                     mflinkrevs.setdefault(changes[0], []).append(i)
                     self.refersmf = True
                 for f in changes[3]:
@@ -594,7 +591,7 @@
                                 % (rp[0], short(rp[1])),
                                 f,
                             )
-                        elif rp[1] == nullid:
+                        elif rp[1] == self.repo.nullid:
                             ui.note(
                                 _(
                                     b"warning: %s@%s: copy source"
diff --git a/mercurial/wireprotov1server.py b/mercurial/wireprotov1server.py
--- a/mercurial/wireprotov1server.py
+++ b/mercurial/wireprotov1server.py
@@ -11,10 +11,7 @@
 import os
 
 from .i18n import _
-from .node import (
-    hex,
-    nullid,
-)
+from .node import hex
 from .pycompat import getattr
 
 from . import (
@@ -469,7 +466,7 @@
         clheads = set(repo.changelog.heads())
         heads = set(opts.get(b'heads', set()))
         common = set(opts.get(b'common', set()))
-        common.discard(nullid)
+        common.discard(repo.nullid)
         if (
             repo.ui.configbool(b'server', b'pullbundle')
             and b'partial-pull' in proto.getprotocaps()
diff --git a/mercurial/wireprotov2server.py b/mercurial/wireprotov2server.py
--- a/mercurial/wireprotov2server.py
+++ b/mercurial/wireprotov2server.py
@@ -10,10 +10,7 @@
 import contextlib
 
 from .i18n import _
-from .node import (
-    hex,
-    nullid,
-)
+from .node import hex
 from . import (
     discovery,
     encoding,
@@ -948,7 +945,7 @@
             if spec[b'roots']:
                 common = [n for n in spec[b'roots'] if clhasnode(n)]
             else:
-                common = [nullid]
+                common = [repo.nullid]
 
             for n in discovery.outgoing(repo, common, spec[b'heads']).missing:
                 if n not in seen:
diff --git a/setup.py b/setup.py
--- a/setup.py
+++ b/setup.py
@@ -816,8 +816,7 @@
                 if sys.version_info[0] >= 3:
                     fsdecode = os.fsdecode
                 dest = os.path.join(
-                    os.path.dirname(self.hgtarget),
-                    fsdecode(dllbasename),
+                    os.path.dirname(self.hgtarget), fsdecode(dllbasename),
                 )
 
                 if not os.path.exists(dest):
diff --git a/tests/drawdag.py b/tests/drawdag.py
--- a/tests/drawdag.py
+++ b/tests/drawdag.py
@@ -299,7 +299,7 @@
         self._added = added
         self._parents = parentctxs
         while len(self._parents) < 2:
-            self._parents.append(repo[node.nullid])
+            self._parents.append(repo[repo.nullid])
 
     def filectx(self, key):
         return simplefilectx(key, self._added[key])
@@ -388,7 +388,7 @@
         content = content.replace(br'\n', b'\n').replace(br'\1', b'\1')
         files[name][path] = content
 
-    committed = {None: node.nullid}  # {name: node}
+    committed = {None: repo.nullid}  # {name: node}
 
     # for leaf nodes, try to find existing nodes in repo
     for name, parents in edges.items():
diff --git a/tests/simplestorerepo.py b/tests/simplestorerepo.py
--- a/tests/simplestorerepo.py
+++ b/tests/simplestorerepo.py
@@ -18,7 +18,6 @@
 from mercurial.node import (
     bin,
     hex,
-    nullid,
     nullrev,
 )
 from mercurial.thirdparty import attr
@@ -106,7 +105,9 @@
 
     _flagserrorclass = simplestoreerror
 
-    def __init__(self, svfs, path):
+    def __init__(self, repo, svfs, path):
+        self.nullid = repo.nullid
+        self._repo = repo
         self._svfs = svfs
         self._path = path
 
@@ -134,18 +135,18 @@
             self._indexbynode[entry[b'node']] = entry
             self._indexbyrev[i] = entry
 
-        self._indexbynode[nullid] = {
-            b'node': nullid,
-            b'p1': nullid,
-            b'p2': nullid,
+        self._indexbynode[self._repo.nullid] = {
+            b'node': self._repo.nullid,
+            b'p1': self._repo.nullid,
+            b'p2': self._repo.nullid,
             b'linkrev': nullrev,
             b'flags': 0,
         }
 
         self._indexbyrev[nullrev] = {
-            b'node': nullid,
-            b'p1': nullid,
-            b'p2': nullid,
+            b'node': self._repo.nullid,
+            b'p1': self._repo.nullid,
+            b'p2': self._repo.nullid,
             b'linkrev': nullrev,
             b'flags': 0,
         }
@@ -158,7 +159,7 @@
                 (0, 0, 0, -1, entry[b'linkrev'], p1rev, p2rev, entry[b'node'])
             )
 
-        self._index.append((0, 0, 0, -1, -1, -1, -1, nullid))
+        self._index.append((0, 0, 0, -1, -1, -1, -1, self._repo.nullid))
 
     def __len__(self):
         return len(self._indexdata)
@@ -286,7 +287,7 @@
             node = nodeorrev
         validatenode(node)
 
-        if node == nullid:
+        if node == self._repo.nullid:
             return b''
 
         rev = self.rev(node)
@@ -323,7 +324,7 @@
     def renamed(self, node):
         validatenode(node)
 
-        if self.parents(node)[0] != nullid:
+        if self.parents(node)[0] != self._repo.nullid:
             return False
 
         fulltext = self.revision(node)
@@ -448,7 +449,7 @@
         deltamode=repository.CG_DELTAMODE_STD,
     ):
         # TODO this will probably break on some ordering options.
-        nodes = [n for n in nodes if n != nullid]
+        nodes = [n for n in nodes if n != self._repo.nullid]
         if not nodes:
             return
         for delta in storageutil.emitrevisions(
@@ -555,7 +556,7 @@
                 continue
 
             # Need to resolve the fulltext from the delta base.
-            if deltabase == nullid:
+            if deltabase == self._repo.nullid:
                 text = mdiff.patch(b'', delta)
             else:
                 text = mdiff.patch(self.revision(deltabase), delta)
@@ -584,11 +585,11 @@
         # This is copied from revlog.py.
         if start is None and stop is None:
             if not len(self):
-                return [nullid]
+                return [self._repo.nullid]
             return [self.node(r) for r in self._headrevs()]
 
         if start is None:
-            start = nullid
+            start = self._repo.nullid
         if stop is None:
             stop = []
         stoprevs = {self.rev(n) for n in stop}
@@ -687,7 +688,7 @@
 
     class simplestorerepo(repo.__class__):
         def file(self, f):
-            return filestorage(self.svfs, f)
+            return filestorage(repo, self.svfs, f)
 
     repo.__class__ = simplestorerepo
 
diff --git a/tests/test-annotate.t b/tests/test-annotate.t
--- a/tests/test-annotate.t
+++ b/tests/test-annotate.t
@@ -479,19 +479,19 @@
 
   $ cat > ../legacyrepo.py <<EOF
   > from __future__ import absolute_import
-  > from mercurial import commit, error, extensions, node
+  > from mercurial import commit, error, extensions
   > def _filecommit(orig, repo, fctx, manifest1, manifest2,
   >                 linkrev, tr, includecopymeta, ms):
   >     fname = fctx.path()
   >     text = fctx.data()
   >     flog = repo.file(fname)
-  >     fparent1 = manifest1.get(fname, node.nullid)
-  >     fparent2 = manifest2.get(fname, node.nullid)
+  >     fparent1 = manifest1.get(fname, repo.nullid)
+  >     fparent2 = manifest2.get(fname, repo.nullid)
   >     meta = {}
   >     copy = fctx.copysource()
   >     if copy and copy != fname:
   >         raise error.Abort('copying is not supported')
-  >     if fparent2 != node.nullid:
+  >     if fparent2 != repo.nullid:
   >         return flog.add(text, meta, tr, linkrev,
   >                         fparent1, fparent2), 'modified'
   >     raise error.Abort('only merging is supported')
diff --git a/tests/test-check-interfaces.py b/tests/test-check-interfaces.py
--- a/tests/test-check-interfaces.py
+++ b/tests/test-check-interfaces.py
@@ -243,7 +243,10 @@
 
     # Conforms to imanifestlog.
     ml = manifest.manifestlog(
-        vfs, repo, manifest.manifestrevlog(repo.svfs), repo.narrowmatch()
+        vfs,
+        repo,
+        manifest.manifestrevlog(repo.nodeconstants, repo.svfs),
+        repo.narrowmatch(),
     )
     checkzobject(ml)
     checkzobject(repo.manifestlog)
@@ -258,7 +261,7 @@
     # Conforms to imanifestdict.
     checkzobject(mctx.read())
 
-    mrl = manifest.manifestrevlog(vfs)
+    mrl = manifest.manifestrevlog(repo.nodeconstants, vfs)
     checkzobject(mrl)
 
     ziverify.verifyClass(repository.irevisiondelta, revlog.revlogrevisiondelta)
diff --git a/tests/test-commit.t b/tests/test-commit.t
--- a/tests/test-commit.t
+++ b/tests/test-commit.t
@@ -646,14 +646,14 @@
 verify pathauditor blocks evil filepaths
   $ cat > evil-commit.py <<EOF
   > from __future__ import absolute_import
-  > from mercurial import context, hg, node, ui as uimod
+  > from mercurial import context, hg, ui as uimod
   > notrc = u".h\u200cg".encode('utf-8') + b'/hgrc'
   > u = uimod.ui.load()
   > r = hg.repository(u, b'.')
   > def filectxfn(repo, memctx, path):
   >     return context.memfilectx(repo, memctx, path,
   >         b'[hooks]\nupdate = echo owned')
-  > c = context.memctx(r, [r.changelog.tip(), node.nullid],
+  > c = context.memctx(r, [r.changelog.tip(), r.nullid],
   >                    b'evil', [notrc], filectxfn, 0)
   > r.commitctx(c)
   > EOF
@@ -672,14 +672,14 @@
   repository tip rolled back to revision 2 (undo commit)
   $ cat > evil-commit.py <<EOF
   > from __future__ import absolute_import
-  > from mercurial import context, hg, node, ui as uimod
+  > from mercurial import context, hg, ui as uimod
   > notrc = b"HG~1/hgrc"
   > u = uimod.ui.load()
   > r = hg.repository(u, b'.')
   > def filectxfn(repo, memctx, path):
   >     return context.memfilectx(repo, memctx, path,
   >         b'[hooks]\nupdate = echo owned')
-  > c = context.memctx(r, [r[b'tip'].node(), node.nullid],
+  > c = context.memctx(r, [r[b'tip'].node(), r.nullid],
   >                    b'evil', [notrc], filectxfn, 0)
   > r.commitctx(c)
   > EOF
@@ -692,14 +692,14 @@
   repository tip rolled back to revision 2 (undo commit)
   $ cat > evil-commit.py <<EOF
   > from __future__ import absolute_import
-  > from mercurial import context, hg, node, ui as uimod
+  > from mercurial import context, hg, ui as uimod
   > notrc = b"HG8B6C~2/hgrc"
   > u = uimod.ui.load()
   > r = hg.repository(u, b'.')
   > def filectxfn(repo, memctx, path):
   >     return context.memfilectx(repo, memctx, path,
   >         b'[hooks]\nupdate = echo owned')
-  > c = context.memctx(r, [r[b'tip'].node(), node.nullid],
+  > c = context.memctx(r, [r[b'tip'].node(), r.nullid],
   >                    b'evil', [notrc], filectxfn, 0)
   > r.commitctx(c)
   > EOF
diff --git a/tests/test-fastannotate-hg.t b/tests/test-fastannotate-hg.t
--- a/tests/test-fastannotate-hg.t
+++ b/tests/test-fastannotate-hg.t
@@ -482,19 +482,19 @@
 
   $ cat > ../legacyrepo.py <<EOF
   > from __future__ import absolute_import
-  > from mercurial import commit, error, extensions, node
+  > from mercurial import commit, error, extensions
   > def _filecommit(orig, repo, fctx, manifest1, manifest2,
   >                 linkrev, tr, includecopymeta, ms):
   >     fname = fctx.path()
   >     text = fctx.data()
   >     flog = repo.file(fname)
-  >     fparent1 = manifest1.get(fname, node.nullid)
-  >     fparent2 = manifest2.get(fname, node.nullid)
+  >     fparent1 = manifest1.get(fname, repo.nullid)
+  >     fparent2 = manifest2.get(fname, repo.nullid)
   >     meta = {}
   >     copy = fctx.copysource()
   >     if copy and copy != fname:
   >         raise error.Abort('copying is not supported')
-  >     if fparent2 != node.nullid:
+  >     if fparent2 != repo.nullid:
   >         return flog.add(text, meta, tr, linkrev,
   >                         fparent1, fparent2), 'modified'
   >     raise error.Abort('only merging is supported')
diff --git a/tests/test-filelog.py b/tests/test-filelog.py
--- a/tests/test-filelog.py
+++ b/tests/test-filelog.py
@@ -4,10 +4,7 @@
 """
 from __future__ import absolute_import, print_function
 
-from mercurial.node import (
-    hex,
-    nullid,
-)
+from mercurial.node import hex
 from mercurial import (
     hg,
     ui as uimod,
@@ -22,7 +19,7 @@
 def addrev(text, renamed=False):
     if renamed:
         # data doesn't matter. Just make sure filelog.renamed() returns True
-        meta = {b'copyrev': hex(nullid), b'copy': b'bar'}
+        meta = {b'copyrev': hex(repo.nullid), b'copy': b'bar'}
     else:
         meta = {}
 
@@ -30,7 +27,7 @@
     try:
         lock = repo.lock()
         t = repo.transaction(b'commit')
-        node = fl.add(text, meta, t, 0, nullid, nullid)
+        node = fl.add(text, meta, t, 0, repo.nullid, repo.nullid)
         return node
     finally:
         if t:
diff --git a/tests/test-manifest.py b/tests/test-manifest.py
--- a/tests/test-manifest.py
+++ b/tests/test-manifest.py
@@ -6,6 +6,8 @@
 import unittest
 import zlib
 
+from mercurial.node import sha1nodeconstants
+
 from mercurial import (
     manifest as manifestmod,
     match as matchmod,
@@ -432,7 +434,7 @@
 
 class testtreemanifest(unittest.TestCase, basemanifesttests):
     def parsemanifest(self, text):
-        return manifestmod.treemanifest(b'', text)
+        return manifestmod.treemanifest(sha1nodeconstants, b'', text)
 
     def testWalkSubtrees(self):
         m = self.parsemanifest(A_DEEPER_MANIFEST)
diff --git a/tests/test-parseindex2.py b/tests/test-parseindex2.py
--- a/tests/test-parseindex2.py
+++ b/tests/test-parseindex2.py
@@ -12,8 +12,8 @@
 import unittest
 
 from mercurial.node import (
-    nullid,
     nullrev,
+    sha1nodeconstants,
 )
 from mercurial import (
     node as nodemod,
@@ -39,7 +39,7 @@
     s = 64
     cache = None
     index = []
-    nodemap = {nullid: nullrev}
+    nodemap = {sha1nodeconstants.nullid: nullrev}
     n = off = 0
 
     l = len(data) - s
@@ -226,7 +226,7 @@
 
         ix = parsers.parse_index2(data_inlined, True)[0]
         for i, r in enumerate(ix):
-            if r[7] == nullid:
+            if r[7] == sha1nodeconstants.nullid:
                 i = -1
             try:
                 self.assertEqual(
@@ -239,7 +239,7 @@
                 break
 
     def testminusone(self):
-        want = (0, 0, 0, -1, -1, -1, -1, nullid)
+        want = (0, 0, 0, -1, -1, -1, -1, sha1nodeconstants.nullid)
         index, junk = parsers.parse_index2(data_inlined, True)
         got = index[-1]
         self.assertEqual(want, got)  # inline data
diff --git a/tests/test-remotefilelog-datapack.py b/tests/test-remotefilelog-datapack.py
--- a/tests/test-remotefilelog-datapack.py
+++ b/tests/test-remotefilelog-datapack.py
@@ -16,7 +16,7 @@
 
 # Load the local remotefilelog, not the system one
 sys.path[0:0] = [os.path.join(os.path.dirname(__file__), '..')]
-from mercurial.node import nullid
+from mercurial.node import sha1nodeconstants
 from mercurial import policy
 
 if not policy._packageprefs.get(policy.policy, (False, False))[1]:
@@ -63,7 +63,14 @@
 
     def createPack(self, revisions=None, packdir=None):
         if revisions is None:
-            revisions = [(b"filename", self.getFakeHash(), nullid, b"content")]
+            revisions = [
+                (
+                    b"filename",
+                    self.getFakeHash(),
+                    sha1nodeconstants.nullid,
+                    b"content",
+                )
+            ]
 
         if packdir is None:
             packdir = self.makeTempDir()
@@ -87,7 +94,7 @@
         filename = b"foo"
         node = self.getHash(content)
 
-        revisions = [(filename, node, nullid, content)]
+        revisions = [(filename, node, sha1nodeconstants.nullid, content)]
         pack = self.createPack(revisions)
         if self.paramsavailable:
             self.assertEqual(
@@ -128,7 +135,7 @@
         """
         revisions = []
         filename = b"foo"
-        lastnode = nullid
+        lastnode = sha1nodeconstants.nullid
         for i in range(10):
             content = b"abcdef%d" % i
             node = self.getHash(content)
@@ -160,7 +167,7 @@
             for j in range(random.randint(1, 100)):
                 content = b"content-%d" % j
                 node = self.getHash(content)
-                lastnode = nullid
+                lastnode = sha1nodeconstants.nullid
                 if len(filerevs) > 0:
                     lastnode = filerevs[random.randint(0, len(filerevs) - 1)]
                 filerevs.append(node)
@@ -188,7 +195,9 @@
                 b'Z': b'random_string',
                 b'_': b'\0' * i,
             }
-            revisions.append((filename, node, nullid, content, meta))
+            revisions.append(
+                (filename, node, sha1nodeconstants.nullid, content, meta)
+            )
         pack = self.createPack(revisions)
         for name, node, x, content, origmeta in revisions:
             parsedmeta = pack.getmeta(name, node)
@@ -202,7 +211,7 @@
         """
         revisions = []
         filename = b"foo"
-        lastnode = nullid
+        lastnode = sha1nodeconstants.nullid
         for i in range(10):
             content = b"abcdef%d" % i
             node = self.getHash(content)
@@ -229,7 +238,7 @@
         pack = self.createPack()
 
         try:
-            pack.add(b'filename', nullid, b'contents')
+            pack.add(b'filename', sha1nodeconstants.nullid, b'contents')
             self.assertTrue(False, "datapack.add should throw")
         except RuntimeError:
             pass
@@ -268,7 +277,9 @@
             content = filename
             node = self.getHash(content)
             blobs[(filename, node)] = content
-            revisions.append((filename, node, nullid, content))
+            revisions.append(
+                (filename, node, sha1nodeconstants.nullid, content)
+            )
 
         pack = self.createPack(revisions)
         if self.paramsavailable:
@@ -292,7 +303,12 @@
 
         for i in range(numpacks):
             chain = []
-            revision = (b'%d' % i, self.getFakeHash(), nullid, b"content")
+            revision = (
+                b'%d' % i,
+                self.getFakeHash(),
+                sha1nodeconstants.nullid,
+                b"content",
+            )
 
             for _ in range(revisionsperpack):
                 chain.append(revision)
@@ -350,7 +366,9 @@
                 filename = b"filename-%d" % i
                 content = b"content-%d" % i
                 node = self.getHash(content)
-                revisions.append((filename, node, nullid, content))
+                revisions.append(
+                    (filename, node, sha1nodeconstants.nullid, content)
+                )
 
             path = self.createPack(revisions).path
 
diff --git a/tests/test-remotefilelog-histpack.py b/tests/test-remotefilelog-histpack.py
--- a/tests/test-remotefilelog-histpack.py
+++ b/tests/test-remotefilelog-histpack.py
@@ -13,7 +13,7 @@
 
 import silenttestrunner
 
-from mercurial.node import nullid
+from mercurial.node import sha1nodeconstants
 from mercurial import (
     pycompat,
     ui as uimod,
@@ -59,8 +59,8 @@
                 (
                     b"filename",
                     self.getFakeHash(),
-                    nullid,
-                    nullid,
+                    sha1nodeconstants.nullid,
+                    sha1nodeconstants.nullid,
                     self.getFakeHash(),
                     None,
                 )
@@ -120,10 +120,19 @@
         """
         revisions = []
         filename = b"foo"
-        lastnode = nullid
+        lastnode = sha1nodeconstants.nullid
         for i in range(10):
             node = self.getFakeHash()
-            revisions.append((filename, node, lastnode, nullid, nullid, None))
+            revisions.append(
+                (
+                    filename,
+                    node,
+                    lastnode,
+                    sha1nodeconstants.nullid,
+                    sha1nodeconstants.nullid,
+                    None,
+                )
+            )
             lastnode = node
 
         # revisions must be added in topological order, newest first
@@ -150,17 +159,17 @@
         for i in range(100):
             filename = b"filename-%d" % i
             entries = []
-            p2 = nullid
-            linknode = nullid
+            p2 = sha1nodeconstants.nullid
+            linknode = sha1nodeconstants.nullid
             for j in range(random.randint(1, 100)):
                 node = self.getFakeHash()
-                p1 = nullid
+                p1 = sha1nodeconstants.nullid
                 if len(entries) > 0:
                     p1 = entries[random.randint(0, len(entries) - 1)]
                 entries.append(node)
                 revisions.append((filename, node, p1, p2, linknode, None))
                 allentries[(filename, node)] = (p1, p2, linknode)
-                if p1 == nullid:
+                if p1 == sha1nodeconstants.nullid:
                     ancestorcounts[(filename, node)] = 1
                 else:
                     newcount = ancestorcounts[(filename, p1)] + 1
@@ -184,10 +193,19 @@
     def testGetNodeInfo(self):
         revisions = []
         filename = b"foo"
-        lastnode = nullid
+        lastnode = sha1nodeconstants.nullid
         for i in range(10):
             node = self.getFakeHash()
-            revisions.append((filename, node, lastnode, nullid, nullid, None))
+            revisions.append(
+                (
+                    filename,
+                    node,
+                    lastnode,
+                    sha1nodeconstants.nullid,
+                    sha1nodeconstants.nullid,
+                    None,
+                )
+            )
             lastnode = node
 
         pack = self.createPack(revisions)
@@ -236,7 +254,14 @@
         pack = self.createPack()
 
         try:
-            pack.add(b'filename', nullid, nullid, nullid, nullid, None)
+            pack.add(
+                b'filename',
+                sha1nodeconstants.nullid,
+                sha1nodeconstants.nullid,
+                sha1nodeconstants.nullid,
+                sha1nodeconstants.nullid,
+                None,
+            )
             self.assertTrue(False, "historypack.add should throw")
         except RuntimeError:
             pass
diff --git a/tests/test-revlog-raw.py b/tests/test-revlog-raw.py
--- a/tests/test-revlog-raw.py
+++ b/tests/test-revlog-raw.py
@@ -8,7 +8,6 @@
 
 from mercurial import (
     encoding,
-    node,
     revlog,
     transaction,
     vfs,
@@ -93,7 +92,7 @@
     '''
     nextrev = len(rlog)
     p1 = rlog.node(nextrev - 1)
-    p2 = node.nullid
+    p2 = rlog.nullid
     if isext:
         flags = revlog.REVIDX_EXTSTORED
     else:
@@ -127,7 +126,7 @@
     class dummychangegroup(object):
         @staticmethod
         def deltachunk(pnode):
-            pnode = pnode or node.nullid
+            pnode = pnode or rlog.nullid
             parentrev = rlog.rev(pnode)
             r = parentrev + 1
             if r >= len(rlog):
@@ -142,7 +141,7 @@
             return {
                 b'node': rlog.node(r),
                 b'p1': pnode,
-                b'p2': node.nullid,
+                b'p2': rlog.nullid,
                 b'cs': rlog.node(rlog.linkrev(r)),
                 b'flags': rlog.flags(r),
                 b'deltabase': rlog.node(deltaparent),
@@ -181,7 +180,7 @@
     dlog = newrevlog(destname, recreate=True)
     for r in rlog:
         p1 = rlog.node(r - 1)
-        p2 = node.nullid
+        p2 = rlog.nullid
         if r == 0 or (rlog.flags(r) & revlog.REVIDX_EXTSTORED):
             text = rlog.rawdata(r)
             cachedelta = None
diff --git a/tests/testlib/ext-sidedata.py b/tests/testlib/ext-sidedata.py
--- a/tests/testlib/ext-sidedata.py
+++ b/tests/testlib/ext-sidedata.py
@@ -10,9 +10,9 @@
 import hashlib
 import struct
 
+from mercurial.node import nullrev
 from mercurial import (
     extensions,
-    node,
     requirements,
     revlog,
     upgrade,
@@ -40,7 +40,7 @@
     text = orig(self, nodeorrev, *args, **kwargs)
     if getattr(self, 'sidedatanocheck', False):
         return text
-    if nodeorrev != node.nullrev and nodeorrev != node.nullid:
+    if nodeorrev != nullrev and nodeorrev != self.nullid:
         sd = self.sidedata(nodeorrev)
         if len(text) != struct.unpack('>I', sd[sidedata.SD_TEST1])[0]:
             raise RuntimeError('text size mismatch')