py3: fix bundle heads to be consumable more than once

contrib/python3-whitelist

@@ -32,8 +32,10 b' test-branch-option.t'
 test-branch-tag-confict.t
 test-branches.t
 test-bundle-phases.t
+test-bundle-r.t
 test-bundle-type.t
 test-bundle-vs-outgoing.t
+test-bundle.t
 test-bundle2-multiple-changegroups.t
 test-bundle2-pushback.t
 test-cappedreader.py

mercurial/commands.py

@@ -1220,7 +1220,7 b' def bundle(ui, repo, fname, dest=None, *'
         other = hg.peer(repo, opts, dest)
         revs = [repo[r].hex() for r in revs]
         revs, checkout = hg.addbranchrevs(repo, repo, branches, revs)
-        heads = revs and map(repo.lookup, revs) or revs
+        heads = revs and pycompat.maplist(repo.lookup, revs) or revs
         outgoing = discovery.findcommonoutgoing(repo, other,
                                                 onlyheads=heads,
                                                 force=opts.get('force'),