Prevent type exception on concatenation if diffstat returns None. This will most often occur if diffstat is not installed in the target platform, though may also happen in other cases where diffstat fails to execute. Signed-off-by: Sean Dague <sean@dague.net>

#!/bin/sh

hg init

echo a > a
hg ci -d '0 0' -Ama

hg an a

echo "[ui]" >> $HGRCPATH
echo "strict=True" >> $HGRCPATH

hg an a
hg annotate a

echo % should succeed - up is an alias, not an abbreviation

hg up