PHP Fatal error: Call-time pass-by-reference has been removed

Question

I have an oldish script and lately I get this error:

Fatal error: Call-time pass-by-reference has been removed in /****/******/public_html/****/cp-list-summary.php on line 100

And it looks like this around line 100 on that file:

if ($row[images])
{
    $image_set = array ();
    $result = mysql_query ('SELECT fname FROM ' . $dbimgs . ' WHERE listid=\'' . $_GET['id'] . '\' ORDER BY id ASC', $link);
    while ($images = mysql_fetch_array ($result))
    {
        array_push (&$image_set, $images[fname]);
    }
}

What causes the error and how to fix it? I'm not a developer, so please take it slow.

Solution 1

You are trying to pass a pointer to your array in array_push. That is why the fatal error is encountered. Simply use:

array_push( $image_set, $images[fname] );

Note: array_push() will raise a warning if the first argument is not an array.

Solution 2

Looks like you site php has being upgraded or you are reusing code from < php 5.3

Simply remove the & on (&$image

Note: There is no reference sign on a function call - only on function definitions. Function definitions alone are enough to correctly pass the argument by reference. As of PHP 5.3.0, you will get a warning saying that "call-time pass-by-reference" is deprecated when you use & in foo(&$a);. And as of PHP 5.4.0, call-time pass-by-reference was removed, so using it will raise a fatal error.

No other expressions should be passed by reference, as the result is undefined.