Ensure that a mapping hashtable size doesn't overflow.
Ensure that a mapping hashtable size doesn't overflow.

Signed-off-by: Felix A. Croes <9c69098d379350e157eff4ad93150662007b8fb2@dworkin.nl>

dworkin/dgd,RetroMud/dgd,dworkin/dgd,RetroMud/dgd,dworkin/dgd