diff -r d4c0fa71de01 -r c96148346af8 hgext/largefiles/overrides.py
--- a/hgext/largefiles/overrides.py	Wed Jan 18 14:33:19 2012 +0100
+++ b/hgext/largefiles/overrides.py	Wed Jan 18 11:33:14 2012 +0100
@@ -658,6 +658,19 @@
         if not source:
             source = 'default'
         result = orig(ui, repo, source, **opts)
+        # If we do not have the new largefiles for any new heads we pulled, we
+        # will run into a problem later if we try to merge or rebase with one of
+        # these heads, so cache the largefiles now direclty into the system
+        # cache.
+        ui.status(_("caching new largefiles\n"))
+        numcached = 0
+        branches = repo.branchmap()
+        for branch in branches:
+            heads = repo.branchheads(branch)
+            for head in heads:
+                (cached, missing) = lfcommands.cachelfiles(ui, repo, head)
+                numcached += len(cached)
+        ui.status(_("%d largefiles cached\n" % numcached))
     return result
 
 def override_rebase(orig, ui, repo, **opts):