Please do not call zval_dtor on recursive array

Hey: recently we found a problem, that is "usage zval_dtor on a recursive array while gc enabled" has chance to result a segfault. a reproduce script could be found here: https://github.com/php/php-src/blob/8bd5e15ff7a57791956c4017ee8fb4a8ac0d8d2e/ext/pcre/tests/bug63055.phpt the preg_match used to call zval_dtor on the third argument. which result a segfault, reported at #63055 the segfault backtrace will looks like: http://pastebin.com/uPWBgrTZ thanks to dmitry, we got a simple solution, that is: instead of directly call to zval_dtor, please use following codes instead: " zval garbage = *subpats; array_init(subpats); zval_dtor(&garbage); " thanks -- Laruence Xinchen Hui http://www.laruence.com/