Description:
------------
ImagePolygon draws broken lines when Antialiasing is 
enabled. See example at http://
glassdbase.unibas.ch/test.php

Reproduce code:
---------------
<?php
$image = imagecreatetruecolor(500, 300);
$bg = imagecolorallocate($image, 0, 0, 0);
$col_poly = imagecolorallocate($image, 255, 255, 255);
$poly = array(35, 190, 42, 191, 45, 192, 48, 186, 51, 182, 63, 180, 78, 175, 91, 177, 115, 185,
		121, 184,
		131, 177,
		174, 133,
		201, 121,
		429, 60,
		435, 82,
		435, 260,
		35, 260
);
imageantialias($image, true);
imagepolygon($image, $poly, count($poly) / 2, $col_poly);
header("Content-type: image/png");
imagepng($image);
?> 

Expected result:
----------------
An antialiased polygon (=no interruption) as described 
in documentation.

Actual result:
--------------
See output of above example at http://
glassdbase.unibas.ch/test.php