commit: rewrite check for `hg ci <path>` being a directory The matcher API is complicated by match.bad, match.explicitdir, and match.traversedir. We already have very few users of match.explicitdir. By rewriting this check we get close to being able to remove match.explicitdir. This may make the check slower, but I think that will be very marginal. Disclosure: I actually wrote this patch to solve a bug we've seen with an internal extension. The internal extension overrides the dirstate walk to only walk the files that our FUSE tells us are modified. That led to "vdirs" not getting populated as this code expected. I have wanted to get rid of match.explicitdir for a very long time, though. Differential Revision: https://phab.mercurial-scm.org/D7437