imagefill() causes segfault when x and y coords are outside image range.

eg:

[pgl@redbox ~]# cat s.php 
<?
Header ("Content-type: image/gif");
$im = imagecreate (500, 500);

$black = ImageColorAllocate ($im, 0, 0, 0);
$red = imagecolorallocate ($im, 255, 0, 0);

imagefill ($im, 500, 1, $red);

ImageGif ($im);
ImageDestroy ($im);
?>
[pgl@redbox ~]# php s.php 
Segmentation fault (core dumped)

uname:

Linux redbox 2.2.17-14enterprise #1 SMP Mon Feb 5 18:31:31 EST 2001 i686 unknown