pathauditor: move file system specific check in their own function

This will make it easy to disable that part when not relevant (eg: auditing
filename for operation in history)

mercurial/pathutil.py

@@ -81,6 +81,18 b' class pathauditor(object):'
             normprefix = os.sep.join(normparts)
             if normprefix in self.auditeddir:
                 break
+            self._checkfs(prefix, path)
+            prefixes.append(normprefix)
+            parts.pop()
+            normparts.pop()
+
+        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"""
             curpath = os.path.join(self.root, prefix)
             try:
                 st = os.lstat(curpath)
@@ -98,16 +110,7 b' class pathauditor(object):'
                       os.path.isdir(os.path.join(curpath, '.hg'))):
                     if not self.callback or not self.callback(curpath):
                         raise error.Abort(_("path '%s' is inside nested "
-                                           "repo %r")
-                                         % (path, prefix))
-            prefixes.append(normprefix)
-            parts.pop()
-            normparts.pop()
-
-        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)
+                                        "repo %r") % (path, prefix))
 
     def check(self, path):
         try: