# HG changeset patch
# User Eric Hopper <hopper@omnifarious.org>
# Date 1128730077 25200
# Node ID 106fdec8e1fb71254e6ae7d89a13482f1c7221c0
# Parent  1033892bbb8748f54bd632aeac467a60a766c97f
Fix small bug in nodesbetween if heads is [nullid].

diff --git a/mercurial/revlog.py b/mercurial/revlog.py
--- a/mercurial/revlog.py
+++ b/mercurial/revlog.py
@@ -310,6 +310,8 @@ class revlog:
                         # So it is, real heads should not be the ancestors of
                         # any other heads.
                         heads.pop(n)
+            if not ancestors:
+                return ([], [], [])
             # Now that we have our set of ancestors, we want to remove any
             # roots that are not ancestors.