Description:
------------
The upgrade from PHP 4.4.4 to 4.4.5 caused a Segmentation Fault on a client's osCommerce site.  I've tracked the problem down to a session_register function call on a undeclared variable.

Reproduce code:
---------------
<?php
session_start();
// Uncomment the following line to prevent the Segmentation Fault
//$myvar = 1;
session_register("myvar");

echo "Hello World";
?>


Expected result:
----------------
Hello World and no "Segmentation Fault" in Apache's error log:

[Sat Feb 17 21:14:16 2007] [notice] child pid 20549 exit signal Segmentation fault (11)

Actual result:
--------------
0x080dbbc2 in php_add_session_var (name=0x850b75c "myvar", namelen=5)
    at /usr/src/apache-php/build/php-4.4.5/ext/session/session.c:287
287                     if ((Z_TYPE_PP(sym_global) == IS_ARRAY && Z_ARRVAL_PP(sym_global) == &EG(symbol_table)) || *sym_global == PS(http_session_vars)) {