Ensure that the functions have already been called

We also need to ensure that the functions to observe have already been
called, so that their begin and end handlers are properly initialized.
Otherwise we will not observe the function execution, but a segfault.

Author: cmb69

ext/zend_test/observer.c

@@ -309,7 +309,7 @@ static ZEND_INI_MH(zend_test_observer_OnUpdateCommaList)
 	}
 	if (stage != PHP_INI_STAGE_STARTUP && stage != PHP_INI_STAGE_ACTIVATE && stage != PHP_INI_STAGE_DEACTIVATE && stage != PHP_INI_STAGE_SHUTDOWN) {
 		ZEND_HASH_FOREACH_STR_KEY(*p, funcname) {
-			if ((func = zend_hash_find_ptr(EG(function_table), funcname))) {
+			if ((func = zend_hash_find_ptr(EG(function_table), funcname)) && ZEND_OBSERVER_DATA(func) != NULL) {
 				zend_observer_remove_begin_handler(func, observer_begin);
 				zend_observer_remove_end_handler(func, observer_end);
 			}
@@ -331,7 +331,7 @@ static ZEND_INI_MH(zend_test_observer_OnUpdateCommaList)
 		zend_string_release(str);
 		if (stage != PHP_INI_STAGE_STARTUP && stage != PHP_INI_STAGE_ACTIVATE && stage != PHP_INI_STAGE_DEACTIVATE && stage != PHP_INI_STAGE_SHUTDOWN) {
 			ZEND_HASH_FOREACH_STR_KEY(*p, funcname) {
-				if ((func = zend_hash_find_ptr(EG(function_table), funcname))) {
+				if ((func = zend_hash_find_ptr(EG(function_table), funcname)) && ZEND_OBSERVER_DATA(func) != NULL) {
 					zend_observer_add_begin_handler(func, observer_begin);
 					zend_observer_add_end_handler(func, observer_end);
 				}