Description:
------------
I'm actually using PHP 5.2.5-pl1-gentoo, but the drop-down was not specific enough.

I don't think that my ./configure is really relevant, but if you have trouble reproducing I'll post it.

Regardless, when parsekit encounters a function whose parameters have initializers if they are unspecified, and they are bound to constants, php_parsekit_define_name_ex() is unable to find them in the lookup list and returns UNKNOWN for the 'constant' field of the op2 field for the opcode ZEND_RECV_INIT. This wouldn't necessarily be a problem, except that it is not technically bound as a string variable. It is actually not identified as a type at all by PHP, and results in a segmentation fault when it is parsed as a string (but other operations can be performed on it, specifically anything that would not incur a type-check).

Reproduce code:
---------------
define ('zero', 0);

function y($x = zero) {
        return $x + 1;
}

$opcodes = parsekit_compile_file($_SERVER['PHP_SELF'], $errors, PARSEKIT_QUIET);

foreach ($opcodes['function_table'] as $func) {
        foreach ($func['opcodes'] as $op) {
                if ($op['opcode'] == PARSEKIT_ZEND_RECV_INIT)
                        var_dump($op);
        }
}


Expected result:
----------------
["op1"]=>
  array(3) {
    ["type"]=>
    int(1)
    ["type_name"]=>
    string(8) "IS_CONST"
    ["constant"]=>
    &int(1)
  }
  ["op2"]=>
  array(3) {
    ["type"]=>
    int(1)
    ["type_name"]=>
    string(8) "IS_CONST"
    ["constant"]=>
    &int(0)            <--- This would be most useful as the constant name, i think. But value would be fine too.
  }


Actual result:
--------------
(... earlier var_dump omitted ...)
["op1"]=>
  array(3) {
    ["type"]=>
    int(1)
    ["type_name"]=>
    string(8) "IS_CONST"
    ["constant"]=>
    &int(1)
  }
  ["op2"]=>
  array(3) {
    ["type"]=>
    int(1)
    ["type_name"]=>
    string(8) "IS_CONST"
    ["constant"]=>
    &UNKNOWN:0          <--- This is untyped and may be a wild pointer. It causes a segfault when a typecast happens.
  }
(... var_dump continues ...)