diff -r 509768fc7542 -r b0c14c5d44b1 mercurial/obsolete.py
--- a/mercurial/obsolete.py	Mon Dec 23 13:32:03 2013 -0800
+++ b/mercurial/obsolete.py	Mon Dec 23 13:33:21 2013 -0800
@@ -440,7 +440,8 @@
 
     Some successors may be unknown locally.
 
-    This is a linear yield unsuited to detecting split changesets."""
+    This is a linear yield unsuited to detecting split changesets. It includes
+    initial nodes too."""
     remaining = set(nodes)
     seen = set(remaining)
     while remaining: