caches: invalidate store caches when lock is taken
The fncache was not being properly invalidated each time the lock was taken, so
in theory it could contain old data from prior to the caller having the lock.
This changes it to be invalidated as soon as the lock is taken (same as all our
other caches).
$ hg init
$ echo a > a
$ hg ci -Am0
adding a
$ hg -q clone . foo
$ touch .hg/store/journal
$ echo foo > a
$ hg ci -Am0
abort: abandoned transaction found - run hg recover!
[255]
$ hg recover
rolling back interrupted transaction
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
Check that zero-size journals are correctly aborted:
#if unix-permissions no-root
$ hg bundle -qa repo.hg
$ chmod -w foo/.hg/store/00changelog.i
$ hg -R foo unbundle repo.hg
adding changesets
abort: Permission denied: $TESTTMP/foo/.hg/store/.00changelog.i-* (glob)
[255]
$ if test -f foo/.hg/store/journal; then echo 'journal exists :-('; fi
#endif