diff --git a/mercurial/upgrade.py b/mercurial/upgrade.py
--- a/mercurial/upgrade.py
+++ b/mercurial/upgrade.py
@@ -561,7 +561,7 @@
         pass # create all the directories
 
     util.copyfile(oldindex, newindex)
-    if oldrl.opener.exists(olddata):
+    if oldrl.opener.exists(oldrl.datafile):
         util.copyfile(olddata, newdata)
 
     if not (unencodedname.endswith('00changelog.i')