# HG changeset patch
# User Sune Foldager <cryo@cyanite.org>
# Date 2009-11-24 08:49:23
# Node ID 806e6b6cb8d84a68ff90a40d2894d7669f31374b
# Parent  f139814d20b335b34f82d0155e807d789b440ea9

ancestor: improve docstring

The term "least common ancestor" is highly ambiguous.

diff --git a/mercurial/ancestor.py b/mercurial/ancestor.py
--- a/mercurial/ancestor.py
+++ b/mercurial/ancestor.py
@@ -9,10 +9,11 @@ import heapq
 
 def ancestor(a, b, pfunc):
     """
-    return the least common ancestor of nodes a and b or None if there
-    is no such ancestor.
+    return a minimal-distance ancestor of nodes a and b, or None if there is no
+    such ancestor. Note that there can be several ancestors with the same
+    (minimal) distance, and the one returned is arbitrary.
 
-    pfunc must return a list of parent vertices
+    pfunc must return a list of parent vertices for a given vertex
     """
 
     if a == b: