Description:
------------
Tested with: 5.2.6(win), 5.2.9(win) and 5.2.9-0.dotdeb.2 (lin).

Writing a value of a SimpleXML-Element in a foreach loop, causes PHP to never leave the foreach loop, if you access that element via an extra index.


Reproduce code:
---------------
error_reporting(E_ALL);
$xmlData = '<root><child><name>A child</name><info><version>1</version></info></child><child><name>B child</name><info><version>2</version></info></child><child><name>C child</name><info><version>2</version></info></child><child><name>D child</name><info><version>3</version></info></child></root>';
$xml = simplexml_load_string($xmlData);
$i = -1;
foreach ($xml as $xi => $child) {
    ++$i;
    $xml->child[$i]->info->version = rand(1,9);
    echo 'I: '.$i.' Xi: '.$xi.' Count : '.count($xml).' '.$xml->child[$i]->name.' => '.$child->name.' v:'.$child->info->version."\n";
    if($i > 10) {
        echo "Too many iterations";
        break;
    }
}
// Code below works as expected
$xml = simplexml_load_string($xmlData);
for($i = 0, $size = count($xml); $i < $size; ++$i) {
    echo 'I: '.$i.' Count : '.count($xml).' '.$xml->child[$i]->name."\n";
    $xml->child[$i]->info->version = rand(1,9);
}

Expected result:
----------------
Something like that:

I: 0 Xi: child Count : 4 A child => A child v:1
I: 1 Xi: child Count : 4 B child => B child v:3
I: 2 Xi: child Count : 4 C child => C child v:3
I: 3 Xi: child Count : 4 D child => D child v:7
I: 0 Count : 4 A child
I: 1 Count : 4 B child
I: 2 Count : 4 C child
I: 3 Count : 4 D child


Actual result:
--------------
I: 1 Xi: child Count : 4 B child => B child v:6
I: 2 Xi: child Count : 4 C child => B child v:6
I: 3 Xi: child Count : 4 D child => B child v:6
I: 4 Xi: child Count : 5  => B child v:6
I: 5 Xi: child Count : 6  => B child v:6
I: 6 Xi: child Count : 7  => B child v:6
I: 7 Xi: child Count : 8  => B child v:6
I: 8 Xi: child Count : 9  => B child v:6
I: 9 Xi: child Count : 10  => B child v:6
I: 10 Xi: child Count : 11  => B child v:6
I: 11 Xi: child Count : 12  => B child v:6
Too many iterations
I: 0 Count : 4 A child
I: 1 Count : 4 B child
I: 2 Count : 4 C child
I: 3 Count : 4 D child