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 "nothing" > a
hg add a
hg commit -m ancestor -d "0 0"
echo "something" > a
hg commit -m branch1 -d "0 0"
hg co 0
echo "something else" > a
hg commit -m branch2 -d "0 0"
HGMERGE=merge; export HGMERGE
hg up -m 1
hg id
grep -Ev ">>>|<<<" a
hg status