Re: [PATCH v4 04/13] dir: fix pattern matching on dirs

This patch changes the behavior of .gitignore such that directories are
now matched by prefix instead of matching exactly.

The failure that we observed is something like the following:

In "a/.gitignore", we have the pattern "git/". We should expect that
"a/git/foo" to be ignored because "git/" should be matched exactly.
However, "a/git-foo/bar" is also ignored because "git-foo" matches the
prefix.

I'll prepare a test case for this as soon as I figure out how to write
it..