Merge branch 'sg/dir-trie-fixes'

Code clean-up and a bugfix in the logic used to tell worktree local and repository global refs apart. * sg/dir-trie-fixes: path.c: don't call the match function without value in trie_find() path.c: clarify two field names in 'struct common_dir' path.c: mark 'logs/HEAD' in 'common_list' as file path.c: clarify trie_find()'s in-code comment Documentation: mention more worktree-specific exceptions