vfs: use checkambigatclosing in checkambig=True but atomictemp=False case
In Mercurial source tree, opening a file in "a"/"a+" mode like below
doesn't specify atomictemp=True for vfs, and this avoids file stat
ambiguity check by atomictempfile.
- writing changes out in revlog layer uses "a+" mode
- truncation in repair.strip() uses "a" mode
- truncation in transaction._playback() uses "a" mode
If steps below occurs at "the same time in sec", all of mtime, ctime
and size are same between (1) and (3).
1. append data to revlog-style file (and close transaction)
2. discard appended data by truncation (strip or rollback)
3. append same size but different data to revlog-style file again
Therefore, cache validation doesn't work after (3) as expected.
This patch uses checkambigatclosing in checkambig=True but
atomictemp=False case, to check (and get rid of) file stat ambiguity
at closing.
This is a part of ExactCacheValidationPlan.
https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan
#require test-repo
Enable obsolescence to avoid the warning issue when obsmarker are found
$ . "$TESTDIR/helpers-testrepo.sh"
Go back in the hg repo
$ cd $TESTDIR/..
$ for node in `hg log --rev 'not public() and ::.' --template '{node|short}\n'`; do
> hg export $node | contrib/check-commit > ${TESTTMP}/check-commit.out
> if [ $? -ne 0 ]; then
> echo "Revision $node does not comply with rules"
> echo '------------------------------------------------------'
> cat ${TESTTMP}/check-commit.out
> echo
> fi
> done