--- a/mercurial/cmdutil.py	Mon Apr 27 16:24:43 2015 -0500
+++ b/mercurial/cmdutil.py	Mon Apr 27 14:02:49 2015 -0700
@@ -161,7 +161,7 @@
             dopatch = fp.tell()
             fp.seek(0)
 
-            [os.unlink(c) for c in newlyaddedandmodifiedfiles]
+            [os.unlink(repo.wjoin(c)) for c in newlyaddedandmodifiedfiles]
             # 3a. apply filtered patch to clean repo  (clean)
             if backups:
                 # Equivalent to hg.revert