mercurial/filelog.py

--- a/mercurial/filelog.py	Tue Mar 16 01:16:04 2010 +0100
+++ b/mercurial/filelog.py	Tue Mar 16 01:16:19 2010 +0100
@@ -59,7 +59,7 @@
         """compare text with a given file revision"""
 
         # for renames, we have to go the slow way
-        if self.renamed(node):
+        if text.startswith('\1\n') or self.renamed(node):
             t2 = self.read(node)
             return t2 != text