wddx_deserialize null dereference in php_wddx_pop_element

Upstream Bug --- https://bugs.php.net/bug.php?id=72799 Summary -- If we add an element to boolean leaf of XML struct, a null pointer dereference will happen when the element is popped. ``` Source code: https://github.com/php/php-src/blob/PHP-5.6.24/ext/wddx/wddx.c#L985 static void php_wddx_pop_element(void *user_data, const XML_Char *name) { ... if (Z_TYPE_P(ent2->data) == IS_ARRAY || Z_TYPE_P(ent2->data) == IS_OBJECT) { target_hash = HASH_OF(ent2->data); ... ``` Patch -- ``` http://git.php.net/?p=php-src.git;a=commit;h=1f6078e4a5c67733bfdbd20bb2706501ac56a344 ``` Fixed for PHP 5.6.25, PHP 7.0.10 -- http://php.net/ChangeLog-5.php http://php.net/ChangeLog-7.php