topic-revset: strictly read string
Making a clear distinction between string and symbol passed to topic is
important when it comes to empty topic. Filtering an empty topic name is
harmless. Searching a non existent revision is not.
# utility to setup pythonpath to point into the tested repository
export SRCDIR=`dirname $TESTDIR`
if [ -n "$PYTHONPATH" ]; then
export HGTEST_ORIG_PYTHONPATH=$PYTHONPATH
export PYTHONPATH=$SRCDIR:$PYTHONPATH
else
export PYTHONPATH=$SRCDIR
fi