1--TEST-- 2Bug #79108: Referencing argument in a function makes it a reference in the stack trace 3--FILE-- 4<?php 5 6function test(string $val) { 7 $a = &$val; 8 hackingHere(); 9 print_r($val); 10} 11 12function hackingHere() { 13 // we're able to modify the $val from here, even though the arg was not a reference 14 debug_backtrace()[1]['args'][0] = 'Modified'; 15} 16 17test('Original'); 18 19?> 20--EXPECT-- 21Original 22