Fixes for push corner case TAH found a bug where push would push things the remote already had, raising an assertion. This turned out to be because the changeset protocol was not recording a common subset node in one case. Also discovered was that the protocol was queueing multiple copies of a node for pull. Fixed by changing fetch to a hash. Add some more debugging output.

#!/bin/sh

hg init
echo "[hooks]" > .hg/hgrc
echo 'precommit = echo precommit hook' >> .hg/hgrc
echo 'commit = echo commit hook: $NODE' >> .hg/hgrc
echo a > a
hg add a
hg commit -m "test" -d "0 0"