Description:
------------
mcrypt_generic_init() issues a PHP warning when an empty IV is supplied (good), even in ECB mode (not so good).

From the PHP documentation: "IV is ignored in ECB."

Since the IV is ignored in ECB mode, PHP should not issue any IV-related warnings.

(Also tested php5.2-200711302330)


Reproduce code:
---------------
<?php
$td = mcrypt_module_open("des", "", "ecb", "");
mcrypt_generic_init($td, "01234567", "");
?>


Expected result:
----------------
I expect the code to run without any warnings.


Actual result:
--------------
Warning: mcrypt_generic_init(): Iv size incorrect; supplied length: 0, needed: 8 in /tmp/php-5.2.5/ecb-test.php on line 3