fix possible nullptr derefrence

diff --git a/ext/standard/basic_functions.c b/ext/standard/basic_functions.c
index b45db8a9b492e9a3ed8b9059328f3eb7c6625a6b..f37ae5614e9567e88aa7df7af320e61bc42acc7c 100644 (file)
--- a/ext/standard/basic_functions.c
+++ b/ext/standard/basic_functions.c
@@ -4861,9 +4861,11 @@ static int user_shutdown_function_call(zval *zv TSRMLS_DC) /* {{{ */
        zend_string *function_name;
 
        if (!zend_is_callable(&shutdown_function_entry->arguments[0], 0, &function_name TSRMLS_CC)) {
-               php_error(E_WARNING, "(Registered shutdown functions) Unable to call %s() - function does not exist", function_name->val);
                if (function_name) {
+                       php_error(E_WARNING, "(Registered shutdown functions) Unable to call %s() - function does not exist", function_name->val);
                        zend_string_release(function_name);
+               } else {
+                       php_error(E_WARNING, "(Registered shutdown functions) Unable to call - function does not exist");
                }
                return 0;
        }