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.
$ . "$TESTDIR/narrow-library.sh"
$ hg init master
$ cd master
$ echo treemanifest >> .hg/requires
$ echo 'contents of file' > file
$ mkdir foo
$ echo 'contents of foo/bar' > foo/bar
$ hg ci -Am 'some change'
adding file
adding foo/bar
$ cd ..
$ hg clone --narrow ssh://user@dummy/master copy --include=foo
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets * (glob)
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd copy
$ hg debugdirstate --no-dates
n * 20 * foo/bar (glob)
$ mv .hg/dirstate .hg/old_dirstate
$ dd bs=40 count=1 if=.hg/old_dirstate of=.hg/dirstate 2>/dev/null
$ hg debugdirstate
$ hg debugrebuilddirstate
$ hg debugdirstate
n * * unset foo/bar (glob)