diff --git a/mercurial/revlog.py b/mercurial/revlog.py
--- a/mercurial/revlog.py
+++ b/mercurial/revlog.py
@@ -407,6 +407,9 @@
         for candidaterevs in self._getcandidaterevs(p1, p2, cachedelta):
             nominateddeltas = []
             for candidaterev in candidaterevs:
+                # no delta for rawtext-changing revs (see "candelta" for why)
+                if revlog.flags(candidaterev) & REVIDX_RAWTEXT_CHANGING_FLAGS:
+                    continue
                 candidatedelta = self._builddeltainfo(revinfo, candidaterev, fh)
                 if revlog._isgooddeltainfo(candidatedelta, revinfo.textlen):
                     nominateddeltas.append(candidatedelta)
@@ -2102,7 +2105,14 @@
             deltacomputer = _deltacomputer(self)
 
         revinfo = _revisioninfo(node, p1, p2, btext, textlen, cachedelta, flags)
-        deltainfo = deltacomputer.finddeltainfo(revinfo, fh)
+
+        # no delta for flag processor revision (see "candelta" for why)
+        # not calling candelta since only one revision needs test, also to
+        # avoid overhead fetching flags again.
+        if flags & REVIDX_RAWTEXT_CHANGING_FLAGS:
+            deltainfo = None
+        else:
+            deltainfo = deltacomputer.finddeltainfo(revinfo, fh)
 
         if deltainfo is not None:
             base = deltainfo.base
diff --git a/tests/test-lfs-bundle.t b/tests/test-lfs-bundle.t
--- a/tests/test-lfs-bundle.t
+++ b/tests/test-lfs-bundle.t
@@ -90,10 +90,7 @@
   ---- Applying src-normal.bundle to dst-normal ----
   OK
   ---- Applying src-normal.bundle to dst-lfs ----
-   X@2: unpacking bcc7d23fa6b7: integrity check failed on data/X.i:2
-   Y@2: unpacking 46017a6640e7: integrity check failed on data/Y.i:2
-  2 integrity errors encountered!
-  (first damaged changeset appears to be 2)
+  CRASHED
   ---- Applying src-lfs.bundle to dst-normal ----
   OK
   ---- Applying src-lfs.bundle to dst-lfs ----
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
@@ -114,6 +114,8 @@
             else:
                 # suboptimal deltaparent
                 deltaparent = min(0, parentrev)
+            if not rlog.candelta(deltaparent, r):
+                deltaparent = -1
             return {'node': rlog.node(r), 'p1': pnode, 'p2': node.nullid,
                     'cs': rlog.node(rlog.linkrev(r)), 'flags': rlog.flags(r),
                     'deltabase': rlog.node(deltaparent),
@@ -151,12 +153,14 @@
     for r in rlog:
         p1 = rlog.node(r - 1)
         p2 = node.nullid
-        if r == 0:
+        if r == 0 or (rlog.flags(r) & revlog.REVIDX_EXTSTORED):
             text = rlog.revision(r, raw=True)
             cachedelta = None
         else:
-            # deltaparent is more interesting if it has the EXTSTORED flag.
-            deltaparent = max([0] + [p for p in range(r - 2) if rlog.flags(p)])
+            # deltaparent cannot have EXTSTORED flag.
+            deltaparent = max([-1] +
+                              [p for p in range(r)
+                               if rlog.flags(p) & revlog.REVIDX_EXTSTORED == 0])
             text = None
             cachedelta = (deltaparent, rlog.revdiff(deltaparent, r))
         flags = rlog.flags(r)
@@ -262,8 +266,9 @@
         result.append((text, rawtext))
 
         # Verify flags like isdelta, isext work as expected
-        if bool(rlog.deltaparent(rev) > -1) != isdelta:
-            abort('rev %d: isdelta is ineffective' % rev)
+        # isdelta can be overridden to False if this or p1 has isext set
+        if bool(rlog.deltaparent(rev) > -1) and not isdelta:
+            abort('rev %d: isdelta is unexpected' % rev)
         if bool(rlog.flags(rev)) != isext:
             abort('rev %d: isext is ineffective' % rev)
     return result