Description:
------------
This is really bug #23935, but that's marked 'Closed' and I am still seeing the problem in the current PHP5 code. It's beyond array_flip(), too, strictly. I first saw this in $_POST with a field named "myfield[1]" - this comes through as $_POST["myfield"]["1"]. Same with array_combine() using array("1") as the key array.

Reproduce code:
---------------
submit a form with hidden field named 'myfield[1]':
<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="POST">
<input type="hidden" name="myfield[1]" value="1" >
<input type="submit">
</form>
<?php
function testit($a)
{
        static $tick = 1;
        echo "<li>test ", $tick++, ":\n";
        var_dump($a, array_key_exists(key($a), $a), empty($a[1]), empty($a['1']));
}
testit(array("1"=>"1"));
testit(array_flip(array(1=>"1")));
testit(array_combine(array('1'),array('1')));
if (!empty($_POST['myfield'])) { testit($_POST['myfield']); }
?>

Expected result:
----------------
Output for test 2 on PHP 4.3.3RC1 (cli) (built: Jun 20 2003 23:09:34) (DEBUG):

array(1) {
  [1]=>
  int(1)
}
bool(true)
bool(false)
bool(false)

Actual result:
--------------
Output for test 2 on PHP 5.0.0b2-dev (cli) (built: Jul 14 2003 14:14:54) (DEBUG):

array(1) {
  ["1"]=>
  int(1)
}
bool(false)
bool(true)
bool(true)