Description:
------------
LOG:
---
php: /home/yongheng/php_clean/Zend/zend_hash.c:731: zval *_zend_hash_add_or_update_i(HashTable *, zend_string *, zval *, uint32_t): Assertion `(zend_gc_refcount(&(ht)->gc) == 1) || ((ht)->u.flags & (1<<6))' failed.
---

Test script:
---------------
<?
try {
    define ( ob_start ( function () {
        global $a ;
        list ( $a ) = $b   ;
    }
    , 20 )  )  ;
}
catch ( Error ) {
    $a [ $c ] = 'x' ;
}