v2: FontNames.c  return a NULL list whenever a single
length field from the server is incohent.
Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
Reviewed-by: Matthieu Herrb <matthieu@herrb.eu>
Backported-to-NX-by: Ulrich Sibiller <uli42@gmx.de>