@NikiC Getting a weird new segfault now in case I have more arguments to a function that it wanted. I used to have:

            if ((i < arguments_wanted) || ((zdata->func->common.fn_flags & ZEND_ACC_CALL_VIA_TRAMPOLINE) && (i < arguments_sent))) {
                if (ZEND_CALL_ARG(zdata, fse->varc+1)) {
                    ZVAL_COPY(&(fse->var[fse->varc].data), ZEND_CALL_ARG(zdata, fse->varc+1));
                }
            } else {
                ZVAL_COPY(&(fse->var[fse->varc].data), ZEND_CALL_VAR_NUM(zdata, zdata->func->op_array.last_var + zdata->func->op_array.T + i - arguments_wanted));
            }

With i being 2 and arguments wanted being 1, for the following code:

    class Test {
    public function __construct() { }
    public function __call($func, $args) {
        return $this->$func($args);
    }
    private function testFunc($args) {
        array_sum($args);
    }

But that now segfaults, because ZEND_CALL_ARG no longer returns "NULL" here.