Description:
------------
xml_set_element_handler segfaults when using a reference to an object or "this" using 4.4 cvs or stock release.


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

class parser {
        var $parser = NULL;
        var $stack = '';

        function parser() {
                $this->parser = xml_parser_create();
                xml_set_element_handler($this->parser, array(&$this, '_startElement'), array(&$this, '_endElement'));
        }

        function _startElement($parser, $tag) {
                $this->stack .= $tag . '/';

        }

        function _endElement($parser, $tag) {
                $this->stack .= $tag . '/';
        }
}

$parser = new parser();



Expected result:
----------------
no segfault.



Actual result:
--------------
Non debug mode ends with:
*** glibc detected *** ./sapi/cli/php: double free or corruption (!prev): 0x0a1a76b0 ***
======= Backtrace: =========
/lib/libc.so.6[0x174424]
/lib/libc.so.6(__libc_free+0x77)[0x17495f]
./sapi/cli/php[0x80fb268]
./sapi/cli/php(php_XML_ParserFree+0x81)[0x80fd305]
./sapi/cli/php[0x80f87d6]
./sapi/cli/php(list_entry_destructor+0x75)[0x813bf4d]
./sapi/cli/php(zend_hash_del_key_or_index+0x15d)[0x813b511]
./sapi/cli/php(_zend_list_delete+0x58)[0x813bd04]
./sapi/cli/php(_zval_ptr_dtor+0x3d)[0x812e995]
./sapi/cli/php(zend_hash_destroy+0x3c)[0x813a32c]
./sapi/cli/php(_zval_dtor+0x3a)[0x8135f9e]
./sapi/cli/php(_zval_ptr_dtor+0x3d)[0x812e995]
./sapi/cli/php(zend_hash_destroy+0x3c)[0x813a32c]
./sapi/cli/php(_zval_dtor+0x80)[0x8135fe4]
./sapi/cli/php(_zval_ptr_dtor+0x3d)[0x812e995]
./sapi/cli/php[0x80f8822]
./sapi/cli/php(list_entry_destructor+0x75)[0x813bf4d]
./sapi/cli/php[0x813a48b]
./sapi/cli/php(zend_hash_graceful_reverse_destroy+0x17)[0x813a5cb]
./sapi/cli/php(shutdown_executor+0xbf)[0x812ea6f]
./sapi/cli/php(zend_deactivate+0x84)[0x8136c68]
./sapi/cli/php(php_request_shutdown+0x15f)[0x810f6a3]
./sapi/cli/php(main+0x148)[0x8151088]
/lib/libc.so.6(__libc_start_main+0xc6)[0x125de6]
./sapi/cli/php[0x8064c2d]


I can provide a backtrace later if required but the script is here :)