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Differential D10150

revlog: guarantee that p1 != null if a non-null parent exists
ClosedPublic

Authored by joerg.sonnenberger on Mar 10 2021, 12:09 PM.

Details

Reviewers
indygreg
durin42
Alphare
Group Reviewers
hg-reviewers
Commits
rHG49fd21f32695: revlog: guarantee that p1 != null if a non-null parent exists
Summary

This change does not affect the hashing (which already did this
transformation), but can change the log output in the rare case where
this behavior was observed in repositories. The change can simplify
iteration code where regular changesets and merges are distinct
branches.

Diff Detail

Repository
rHG Mercurial
Lint
Automatic diff as part of commit; lint not applicable.
Unit
Automatic diff as part of commit; unit tests not applicable.

Revision Contents
Changeset List

PathPackages
Mmercurial/revlog.py (12 lines)
Mrelnotes/next (7 lines)
Mtests/test-narrow-shallow-merges.t (2 lines)

Diff 26488

mercurial/revlog.py

def parentrevs(self, rev): def parentrevs(self, rev):
try: try:
entry = self.index[rev] entry = self.index[rev]
except IndexError: except IndexError:
if rev == wdirrev: if rev == wdirrev:
raise error.WdirUnsupported raise error.WdirUnsupported
raise raise
if entry[5] == nullrev:
return entry[6], entry[5]
else:
return entry[5], entry[6] return entry[5], entry[6]
# fast parentrevs(rev) where rev isn't filtered # fast parentrevs(rev) where rev isn't filtered
_uncheckedparentrevs = parentrevs _uncheckedparentrevs = parentrevs
def node(self, rev): def node(self, rev):
try: try:
return self.index[rev][7] return self.index[rev][7]
except IndexError: except IndexError:
if rev == wdirrev: if rev == wdirrev:
raise error.WdirUnsupported raise error.WdirUnsupported
raise raise
# Derived from index values. # Derived from index values.
def end(self, rev): def end(self, rev):
return self.start(rev) + self.length(rev) return self.start(rev) + self.length(rev)
def parents(self, node): def parents(self, node):
i = self.index i = self.index
d = i[self.rev(node)] d = i[self.rev(node)]
return i[d[5]][7], i[d[6]][7] # map revisions to nodes inline # inline node() to avoid function call overhead
if d[5] == nullid:
return i[d[6]][7], i[d[5]][7]
else:
return i[d[5]][7], i[d[6]][7]
def chainlen(self, rev): def chainlen(self, rev):
return self._chaininfo(rev)[0] return self._chaininfo(rev)[0]
def _chaininfo(self, rev): def _chaininfo(self, rev):
chaininfocache = self._chaininfocache chaininfocache = self._chaininfocache
if rev in chaininfocache: if rev in chaininfocache:
return chaininfocache[rev] return chaininfocache[rev]

relnotes/next

== Bug Fixes == == Bug Fixes ==
== Backwards Compatibility Changes == == Backwards Compatibility Changes ==
* In normal repositories, the first parent of a changeset is not null,
unless both parents are null (like the first changeset). Some legacy
repositories violate this condition. The revlog code will now
silentely swap the parents if this condition is tested. This can
change the output of `hg log` when explicitly asking for first or
second parent.
== Internal API Changes == == Internal API Changes ==
* `changelog.branchinfo` is deprecated and will be removed after 5.8. * `changelog.branchinfo` is deprecated and will be removed after 5.8.
It is superseded by `changelogrevision.branchinfo`. It is superseded by `changelogrevision.branchinfo`.
* Callbacks for revlog.addgroup and the changelog._nodeduplicatecallback hook * Callbacks for revlog.addgroup and the changelog._nodeduplicatecallback hook
now get a revision number as argument instead of a node. now get a revision number as argument instead of a node.
* revlog.addrevision returns the revision number instead of the node. * revlog.addrevision returns the revision number instead of the node.

tests/test-narrow-shallow-merges.t

| o 2 d1c61993ec83... outside 2d | o 2 d1c61993ec83... outside 2d
| |
o 1 bb96a08b062a inside 3 o 1 bb96a08b062a inside 3
| |
o 0 b844052e7b3b... outside 2c o 0 b844052e7b3b... outside 2c
$ hg log -T '{if(ellipsis,"...")}{node|short} {p1node|short} {p2node|short} {desc}\n' | sort $ hg log -T '{if(ellipsis,"...")}{node|short} {p1node|short} {p2node|short} {desc}\n' | sort
...2a20009de83e 000000000000 3ac1f5779de3 outside 10 ...2a20009de83e 3ac1f5779de3 000000000000 outside 10
...3ac1f5779de3 bb96a08b062a 465567bdfb2d merge a/b/c/d 9 ...3ac1f5779de3 bb96a08b062a 465567bdfb2d merge a/b/c/d 9
...8d874d57adea 7ef88b4dd4fa 000000000000 outside 12 ...8d874d57adea 7ef88b4dd4fa 000000000000 outside 12
...b844052e7b3b 000000000000 000000000000 outside 2c ...b844052e7b3b 000000000000 000000000000 outside 2c
...d1c61993ec83 000000000000 000000000000 outside 2d ...d1c61993ec83 000000000000 000000000000 outside 2d
465567bdfb2d d1c61993ec83 000000000000 inside 3 465567bdfb2d d1c61993ec83 000000000000 inside 3
7ef88b4dd4fa 2a20009de83e 000000000000 inside 11 7ef88b4dd4fa 2a20009de83e 000000000000 inside 11
bb96a08b062a b844052e7b3b 000000000000 inside 3 bb96a08b062a b844052e7b3b 000000000000 inside 3