diff --git a/mercurial/upgrade.py b/mercurial/upgrade.py
--- a/mercurial/upgrade.py
+++ b/mercurial/upgrade.py
@@ -465,8 +465,8 @@
         idx = rl.index
         for rev in rl:
             e = idx[rev]
-            datasize += e[1]
-            rawsize += e[2]
+            datasize += e.chunklength
+            rawsize += e.rawlength
 
         srcsize += datasize
         srcrawsize += rawsize
@@ -552,7 +552,7 @@
         datasize = 0
         idx = newrl.index
         for rev in newrl:
-            datasize += idx[rev][1]
+            datasize += idx[rev].chunklength
 
         dstsize += datasize