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Subject: big reference bug in (at least) PHP 5.0.5
From: r.korving@xit.nl ("Ron Korving")

My apologies for my DOM-mistake today, but right now I came across something
that totally stunned me. It's a total paradox situation that just has to be
one of the biggest bugs I've ever come across in PHP. Personally, I think
it's rather high-priority because it's an engine problem, and not an issue
with some extension.

Here's the code:

<?php
  $array = array();

  for ($i=0; $i < 3; $i++)
    $array[] = array("foo" => $i);

  foreach ($array as &$item)
    $item["bar"] = $item["foo"] * 2;

  print_r($array);

  foreach ($array as $item)
    print_r($item);
?>

The expected result would be to see whatever is in the array twice. Once in
the big print_r() on $array, and once per element of $array.

Here's the actual result (look at the last array element):

Array
(
    [0] => Array
        (
            [foo] => 0
            [bar] => 0
        )

    [1] => Array
        (
            [foo] => 1
            [bar] => 2
        )

    [2] => Array
        (
            [foo] => 2
            [bar] => 4
        )

)
Array
(
    [foo] => 0
    [bar] => 0
)
Array
(
    [foo] => 1
    [bar] => 2
)
Array
(
    [foo] => 1
    [bar] => 2
)

So referencing wih foreach() is obviously buggy.
With this foreach it works just fine:

  foreach ($array as $i => $item)
    $array[$i]["bar"] = $item["foo"] * 2;


I fear this bug is not just present in PHP 5.0.5, but in older versions too.

Ron Korving