context: don't complain about a matcher's subrepo paths in changectx.walk() Previously, the first added test printed the following: $ hg files -S -r '.^' sub1/sub2/folder sub1/sub2/folder: no such file in rev 9bb10eebee29 sub1/sub2/folder: no such file in rev 9bb10eebee29 sub1/sub2/folder/test.txt One warning occured each time a subrepo was crossed into. The second test ensures that the matcher copy stays in place. Without the copy, the bad() function becomes an increasingly longer chain, and no message would be printed out for a file missing in the subrepo because the predicate would match in one of the replaced methods. Manifest doesn't know anything about subrepos, so it needs help ignoring subrepos when complaining about bad files.