diff -r 0f0b204b399c -r 94f77624dbb5 mercurial/revlog.py
--- a/mercurial/revlog.py	Tue Aug 19 01:12:56 2014 +0200
+++ b/mercurial/revlog.py	Tue Aug 19 01:13:10 2014 +0200
@@ -753,7 +753,7 @@
         return a in self.commonancestorsheads(a, b)
 
     def ancestor(self, a, b):
-        """calculate the least common ancestor of nodes a and b"""
+        """calculate the "best" common ancestor of nodes a and b"""
 
         a, b = self.rev(a), self.rev(b)
         try: