match: strengthen visit_children_set invariant, Recursive means "all files"
My previous interpretation of "Recursive" was too relaxed: I thought it
instructed the caller to do something like this:
> you can stop calling `visit_children_set` because you'll need to descend into
> every directory recursively, but you should still check every file if it
> matches or not
Whereas the real instruction seems to be:
> I guarantee that everything in this subtree matches, you can stop
> querying the matcher for all files and dirs altogether.
The evidence to support this:
- the test actually passes with the stronger invariant, revealing no
exceptions from this rule
- the implementation of `visit_children_set` for `DifferenceMatcher`
clearly relies on this requirement, so it must hold for that not to
lead to bugs.
#testcases dirstate-v1 dirstate-v2
#if dirstate-v2
$ cat >> $HGRCPATH << EOF
> [format]
> use-dirstate-v2=1
> [storage]
> dirstate-v2.slow-path=allow
> EOF
#endif
Checking the size/permissions/file-type of files stored in the
dirstate after an update where the files are changed concurrently
outside of hg's control.
$ hg init repo
$ cd repo
$ echo a > a
$ hg commit -qAm _
$ echo aa > a
$ hg commit -m _
# this sleep is there to ensure current time has -at-least- one second away
# from the current time. It ensure the mtime is not ambiguous. If the test
# "sleep" longer this will be fine.
# It is not used to synchronise parallele operation so it is "fine" to use it.
$ sleep 1
$ hg status
$ hg debugdirstate --no-dates
n 644 3 (set |unset) a (re)
$ cat >> $TESTTMP/dirstaterace.py << EOF
> import time
> from mercurial import (
> commit,
> extensions,
> merge,
> )
> def extsetup(ui):
> extensions.wrapfunction(merge, 'applyupdates', wrap(0))
> extensions.wrapfunction(commit, 'commitctx', wrap(1))
> def wrap(duration):
> def new(orig, *args, **kwargs):
> res = orig(*args, **kwargs)
> with open("a", "w"):
> pass # just truncate the file
> time.sleep(duration)
> return res
> return new
> EOF
Do an update where file 'a' is changed between hg writing it to disk
and hg writing the dirstate. The dirstate is correct nonetheless, and
so hg status correctly shows a as clean.
$ hg up -r 0 --config extensions.race=$TESTTMP/dirstaterace.py
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg debugdirstate --no-dates
n 644 2 (set |unset) a (re)
$ echo a > a; hg status; hg diff
Do a commit where file 'a' is changed between hg committing its new
revision into the repository, and the writing of the dirstate.
This used to results in a corrupted dirstate (size did not match committed size).
$ echo aaa > a; hg commit -qm _
$ hg merge -qr 1; hg resolve -m; rm a.orig
warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
(no more unresolved files)
$ cat a
<<<<<<< working copy: be46f74ce38d - test: _
aaa
=======
aa
>>>>>>> merge rev: eb3fc6c17aa3 - test: _
$ hg debugdirstate --no-dates
m 0 -2 (set |unset) a (re)
$ hg commit -m _ --config extensions.race=$TESTTMP/dirstaterace.py
$ hg debugdirstate --no-dates
n 0 -1 unset a
$ cat a | wc -c
*0 (re)
$ hg cat -r . a | wc -c
*105 (re)
$ hg status; hg diff --stat
M a
a | 5 -----
1 files changed, 0 insertions(+), 5 deletions(-)