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

  $ rm -rf r

  $ hg init r
  $ cd r
  $ mkdir d1
  $ mkdir d2
  $ touch d1/f d2/f
  $ hg commit -Am '.'
  adding d1/f
  adding d2/f
  $ echo 'syntax:re' >> .hgignore
  $ echo '^d1$' >> .hgignore
  $ hg commit -Am "ignore d1"
  adding .hgignore

Now d1 is a directory that's both committed and ignored.
Untracked files in d2 are still shown, but ones in d1 are ignored:

  $ touch d1/g
  $ touch d2/g
  $ RAYON_NUM_THREADS=1 hg status
  ? d2/g