merge: fix a copy detection bug (issue672) When merging rev1 and rev2, we want to search for copies that happened in rev1 but not in rev2 and vice-versa. We were starting the search at rev1/rev2 and then going back, stopping as soon as we reached the revno of the ancestor, but that can miss some cases (see the new test-issue672). Now we calculate the revisions that are ancestors of rev1 or rev2 (but not both) and make sure the search doesn't stop too early. Simplified test provided by mpm, based on a test case provided by Edward Lee.

#!/bin/sh

set -e

echo "[extensions]" >> $HGRCPATH
echo "hbisect=" >> $HGRCPATH

echo % init
hg init

echo % committing changes
count=0
echo > a
while test $count -lt 32 ; do
    echo 'a' >> a
    test $count -eq 0 && hg add
    hg ci -m "msg $count" -d "$count 0"
    echo % committed changeset $count
    count=`expr $count + 1`
done

echo % log
hg log

echo % hg up -C
hg up -C

echo % bisect test
hg bisect init
hg bisect bad
hg bisect good 1
hg bisect good
hg bisect good
hg bisect good
hg bisect bad
hg bisect good