tests/test-unbundlehash.t

treediscovery: fix regression when run against older repos (issue2793)

I ran the entire test suite with "known" and "getbundle" disabled in
localrepository. This generated failures because the old findoutgoing
had always queried remote's heads explicitly and thus always got them
back in the returned heads. treediscovery.findcommonincoming now
correctly returns remote's heads in all cases.

Also adds a dedicated test for running treediscovery against a
pre-getbundle HTTP server.

Test wire protocol unbundle with hashed heads (capability: unbundlehash)

Create a remote repository.

  $ hg init remote
  $ hg serve -R remote --config web.push_ssl=False --config web.allow_push=* -p $HGPORT -d --pid-file=hg1.pid -E error.log -A access.log
  $ cat hg1.pid >> $DAEMON_PIDS

Clone the repository and push a change.

  $ hg clone http://localhost:$HGPORT/ local
  no changes found
  updating to branch default
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ touch local/README
  $ hg ci -R local -A -m hoge
  adding README
  $ hg push -R local
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files

Ensure hashed heads format is used.
The hash here is always the same since the remote repository only has the null head.

  $ cat access.log | grep unbundle
  * - - [*] "POST /?cmd=unbundle HTTP/1.1" 200 - x-hgarg-1:heads=686173686564+6768033e216468247bd031a0a2d9876d79818f8f (glob)