mercurial/templater.py

--- a/mercurial/templater.py	Wed Oct 26 22:50:06 2016 +0900
+++ b/mercurial/templater.py	Sun Oct 23 14:05:23 2016 +0900
@@ -840,13 +840,8 @@
     cl = mapping['ctx']._repo.changelog
     def isvalid(test):
         try:
-            try:
-                cl.index.partialmatch(test)
-            except AttributeError:
-                # Pure mercurial doesn't support partialmatch on the index.
-                # Fallback to the slow way.
-                if cl._partialmatch(test) is None:
-                    return False
+            if cl._partialmatch(test) is None:
+                return False
 
             try:
                 i = int(test)