pathutil: mark parent directories as audited as we go

Before 0b7ce0b16d8a (pathauditor: change parts verification order to
be root first, 2016-02-11), we used to validate child directories
before parents. It was then important to only mark the child audited
only after we had audited its parent (ancestors). I'm pretty sure we
don't need to do that any more, now that we audit parents before
children.

Differential Revision: https://phab.mercurial-scm.org/D8002

mercurial/pathutil.py

@@ -99,7 +99,6 b' class pathauditor(object):'
 
         parts.pop()
         normparts.pop()
-        prefixes = []
         # It's important that we check the path parts starting from the root.
         # This means we won't accidentally traverse a symlink into some other
         # filesystem (which is potentially expensive to access).
@@ -110,13 +109,11 b' class pathauditor(object):'
                 continue
             if self._realfs:
                 self._checkfs(prefix, path)
-            prefixes.append(normprefix)
+            if self._cached:
+                self.auditeddir.add(normprefix)
 
         if self._cached:
             self.audited.add(normpath)
-            # only add prefixes to the cache after checking everything: we don't
-            # want to add "foo/bar/baz" before checking if there's a "foo/.hg"
-            self.auditeddir.update(prefixes)
 
     def _checkfs(self, prefix, path):
         """raise exception if a file system backed check fails"""