hg parents: don't pass an OS-specific path to repo.filectx The only reason to use the matcher code instead of calling util.canonpath directly is to be able to use "path:canonical/path/to/file" patterns.

# should print nothing
# should print ? b/x
? b/x
# should print A b/x
A b/x
# should forget b/x
forgetting b/x
# should print nothing