merge: don't overwrite untracked file at directory rename target When a directory was renamed and a new untracked file was added in the new directory and the remote directory added a file by the same name in the old directory, the local untracked file gets overwritten, as demonstrated by the broken test case in test-rename-dir-merge. Fix by checking for unknown files for 'dg' actions too. Since _checkunknownfile() currently expects the same filename in both contexts, we need to add a new parameter for the remote filename to it.