bundlerepo: don't return the peer without bundlerepo from getremotechanges

Problem:
getremotechanges would return the 'other' repo if nothing was incoming and
there thus wasn't any bundle to base the repo on. The 'other' could be a http
peer which only implement the functionality available over the http protocol.
Transplant could thus fail with
  TypeError: argument of type 'httppeer' is not iterable

Solution:
Return the local repo instead of the remote peer if there is no reason to place
a bundlerepo on top of the local repo.

mercurial/bundlerepo.py

@@ -347,7 +347,7 b' def getremotechanges(ui, repo, other, on'
                 os.unlink(bundlename)
         except OSError:
             pass
-        return other, [], other.close
+        return repo, [], other.close
 
     bundle = None
     bundlerepo = None

tests/test-transplant.t

@@ -288,6 +288,15 b' remote transplant with pull'
   1  b1
   0  r1
 
+remote transplant without pull
+
+  $ hg pull -q http://localhost:$HGPORT/
+  $ hg transplant -s http://localhost:$HGPORT/ 2 4
+  searching for changes
+  skipping already applied revision 2:8d9279348abb
+  applying 722f4667af76
+  722f4667af76 transplanted to 76e321915884
+
 transplant --continue
 
   $ hg init ../tc