--- a/hgext/graphlog.py	Fri Aug 05 00:39:54 2011 +0200
+++ b/hgext/graphlog.py	Wed Aug 10 13:25:35 2011 -0500
@@ -95,6 +95,8 @@
         elif start == end:
             interline[2 * start] = "|"
         else:
+            if 2 * end >= len(nodeline):
+                continue
             nodeline[2 * end] = "+"
             if start > end:
                 (start, end) = (end, start)