( )⚙ D10034 narrow: fix flaky behavior described in issue6150

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Differential D10034

narrow: fix flaky behavior described in issue6150
ClosedPublic

Authored by Alphare on Feb 19 2021, 1:38 PM.

Details

Reviewers
durin42
Group Reviewers
hg-reviewers
Commits
rHGb994db7c4d1e: narrow: fix flaky behavior described in issue6150
Summary

This has been plaguing the CI for a good while, and it doesn't appear to have
an easy fix proposed yet. The solution in this change is to always do an
unambiguous (but expensive) lookup in case of comparison. This should always
be correct, albeit suboptimal.

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.

Event Timeline

Alphare created this revision.Feb 19 2021, 1:38 PM
Alphare added a comment.Feb 19 2021, 1:39 PM

/!\ This change is destined for the stable branch

Alphare added a commit: rHGb994db7c4d1e: narrow: fix flaky behavior described in issue6150.Feb 24 2021, 11:07 AM
This revision was not accepted when it landed; it landed in state Needs Review.
Closed by commit rHGb994db7c4d1e: narrow: fix flaky behavior described in issue6150 (authored by Alphare). · Explain Why
This revision was automatically updated to reflect the committed changes.

Revision Contents
Changeset List

PathPackages
Mmercurial/filelog.py (16 lines)
Mtests/test-narrow-shallow.t (22 lines)

Diff 25868

mercurial/filelog.py

# the base renamed() to report accurate results. # the base renamed() to report accurate results.
node = self.node(rev) node = self.node(rev)
if super(narrowfilelog, self).renamed(node): if super(narrowfilelog, self).renamed(node):
return len(self.read(node)) return len(self.read(node))
else: else:
return super(narrowfilelog, self).size(rev) return super(narrowfilelog, self).size(rev)
def cmp(self, node, text): def cmp(self, node, text):
different = super(narrowfilelog, self).cmp(node, text) # We don't call `super` because narrow parents can be buggy in case of a
# ambiguous dirstate. Always take the slow path until there is a better
# fix, see issue6150.
# Censored files compare against the empty file.
if self.iscensored(self.rev(node)):
return text != b''
# Because renamed() may lie, we may get false positives for return self.read(node) != text
# different content. Check for this by comparing against the original
# renamed() implementation.
if different:
if super(narrowfilelog, self).renamed(node):
t2 = self.read(node)
return t2 != text
return different

tests/test-narrow-shallow.t

6: Commit rev3 of f9, d1/f9, d2/f9 6: Commit rev3 of f9, d1/f9, d2/f9
5: Commit rev3 of f8, d1/f8, d2/f8 5: Commit rev3 of f8, d1/f8, d2/f8
4...: Commit rev3 of f7, d1/f7, d2/f7 4...: Commit rev3 of f7, d1/f7, d2/f7
3: Commit rev2 of f10, d1/f10, d2/f10 3: Commit rev2 of f10, d1/f10, d2/f10
2: Commit rev2 of f9, d1/f9, d2/f9 2: Commit rev2 of f9, d1/f9, d2/f9
1: Commit rev2 of f8, d1/f8, d2/f8 1: Commit rev2 of f8, d1/f8, d2/f8
0...: Commit rev2 of f7, d1/f7, d2/f7 0...: Commit rev2 of f7, d1/f7, d2/f7
XXX flaky output (see issue6150)
XXX
XXX The filectx implementation is buggy and return wrong data during status.
XXX Leading to more file being "merged". The right output is the one with just
XXX 10 files updated.
$ hg update 4 $ hg update 4
merging d2/f1 (?) 10 files updated, 0 files merged, 0 files removed, 0 files unresolved
merging d2/f2 (?)
merging d2/f3 (?)
merging d2/f4 (?)
merging d2/f5 (?)
merging d2/f6 (?)
merging d2/f7 (?)
3 files updated, 7 files merged, 0 files removed, 0 files unresolved (?)
4 files updated, 6 files merged, 0 files removed, 0 files unresolved (?)
5 files updated, 5 files merged, 0 files removed, 0 files unresolved (?)
6 files updated, 4 files merged, 0 files removed, 0 files unresolved (?)
7 files updated, 3 files merged, 0 files removed, 0 files unresolved (?)
8 files updated, 2 files merged, 0 files removed, 0 files unresolved (?)
9 files updated, 1 files merged, 0 files removed, 0 files unresolved (?)
10 files updated, 0 files merged, 0 files removed, 0 files unresolved (?)
$ cat d2/f7 d2/f8 $ cat d2/f7 d2/f8
d2/f7 rev3 d2/f7 rev3
d2/f8 rev2 d2/f8 rev2
$ hg update 7 $ hg update 7
3 files updated, 0 files merged, 0 files removed, 0 files unresolved 3 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat d2/f10 $ cat d2/f10
d2/f10 rev3 d2/f10 rev3