diff -r 96d3d340f6ec -r 801533a52799 mercurial/changegroup.py
--- a/mercurial/changegroup.py	Thu Jul 22 10:49:55 2010 +0200
+++ b/mercurial/changegroup.py	Thu Jul 22 14:34:37 2010 +0200
@@ -61,8 +61,7 @@
     # We want to gather manifests needed and filelogs affected.
     def collect(node):
         c = cl.read(node)
-        for fn in c[3]:
-            files.setdefault(fn, fn)
+        files.update(c[3])
         mmfs.setdefault(c[0], node)
     return collect