diff -r 984b4554ddf7 -r 24cda1dd45ff mercurial/context.py
--- a/mercurial/context.py	Tue Jun 30 23:34:12 2015 +0800
+++ b/mercurial/context.py	Sun Jun 28 13:38:03 2015 -0400
@@ -1247,10 +1247,7 @@
         return self._extra
 
     def tags(self):
-        t = []
-        for p in self.parents():
-            t.extend(p.tags())
-        return t
+        return []
 
     def bookmarks(self):
         b = []