Only hg repositories override [paths], not simple directories (fixes issue510)

mercurial/ui.py

@@ -362,7 +362,7 b' class ui(object):'
 
     def expandpath(self, loc, default=None):
         """Return repository location relative to cwd or from [paths]"""
-        if "://" in loc or os.path.isdir(loc):
+        if "://" in loc or os.path.isdir(os.path.join(loc, '.hg')):
             return loc
 
         path = self.config("paths", loc)