--TEST-- Bug #69079 (enhancement for mb_substitute_character) --SKIPIF-- --FILE-- --EXPECTF-- bool(true) string(8) "f09f9880" Warning: mb_substitute_character(): Unknown character in %s on line %d bool(false) string(2) "3f" Warning: mb_substitute_character(): Unknown character in %s on line %d string(2) "63" string(6) "8fa1ef"