BUG #5243: Segmentation fault when sending null to crypt();

The following bug has been logged online:

Bug reference:      5243
Logged by:          Greg Johnson
Email address:      greg.johnson@interprose.com
PostgreSQL version: 8.4.1, 8.3.8
Operating system:   CentOS 5.4
Description:        Segmentation fault when sending null to crypt();
Details:

Postgresql version 8.4.1 and 8.3.8 both seg fault when you pass null into
crypt function.

select crypt(null, gen_salt('md5'));

Server Log
----------------------------
LOG:  statement: select crypt(null, gen_salt('md5'));
LOG:  server process (PID 25855) was terminated by signal 11: Segmentation
fault
LOG:  terminating any other active server processes
FATAL:  the database system is in recovery mode
WARNING:  terminating connection because of crash of another server process
DETAIL:  The postmaster has commanded this server process to roll back the
current transaction and exit, because another server process exited
abnormally and possibly corrupted shared memory.
HINT:  In a moment you should be able to reconnect to the database and
repeat your command.