Description:
------------
Tested with php5.3-200810301330 (bug happened with previous snapshots).

It seems restore_error_handler is not working and crashed PHP.
See reproduce code below.

Same code working as expected with PHP 5.2.3 (cli)

This bug may be similar to Bug #46196, but PHP also crashed with message "zend_mm_heap corrupted".


Reproduce code:
---------------
<?php

var_dump ( set_error_handler ('myErrorHandler') );
restore_error_handler  ();
var_dump ( set_error_handler ('myErrorHandler') );

function myErrorHandler($errno, $errstr, $errfile, $errline)
{
    return true;
}


Expected result:
----------------
NULL
NULL

Actual result:
--------------
NULL
string(14) "myErrorHandler"
zend_mm_heap corrupted