evolve: use right value for branch name when finding branch heads
subbranch already formatted as "branchname:topicname", again appending it
with ":topicname" doesn't not make sense.
It's a little bit surprising that no tests fails though.
#!/bin/sh
. $TESTDIR/testlib/pythonpath.sh
# This file holds logic that is used in many tests.
# It can be called in a test like this:
# $ . "$TESTDIR/testlib/topic_setup.sh"
# Enable obsolete markers and enable extensions
cat >> $HGRCPATH << EOF
[experimental]
evolution=createmarkers,exchange
[extensions]
rebase=
topic=
EOF