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.
$ cat > abortcommit.py <<EOF
> from mercurial import error
> def hook(**args):
> raise error.Abort(b"no commits allowed")
> def reposetup(ui, repo):
> repo.ui.setconfig(b"hooks", b"pretxncommit.nocommits", hook)
> EOF
$ abspath=`pwd`/abortcommit.py
$ cat <<EOF >> $HGRCPATH
> [extensions]
> mq =
> abortcommit = $abspath
> EOF
$ hg init foo
$ cd foo
$ echo foo > foo
$ hg add foo
mq may keep a reference to the repository so __del__ will not be
called and .hg/journal.dirstate will not be deleted:
$ hg ci -m foo
error: pretxncommit.nocommits hook failed: no commits allowed
transaction abort!
rollback completed
abort: no commits allowed
[255]
$ hg ci -m foo
error: pretxncommit.nocommits hook failed: no commits allowed
transaction abort!
rollback completed
abort: no commits allowed
[255]
$ cd ..