Description:
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Bundled GD2 in 4.3.4, 4.3.5 and 4.3.6 crashes when antialias is enabled.

When antialias is enabled through the imageantialias($img,$flag) function then the Apache process crashes when trying to paint a line at the edge of the image.

This is reproducible 100% using Apache 1.3.28 on our setup. If antialias is disabled everything works fine.

It seems to be a boundary problem on the edge of the image. See example below.





Reproduce code:
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<?php
// 
// This script will generate a Seg Fault on Linux
//
$im  = imagecreatetruecolor(300, 300);
$w  = imagecolorallocate($im, 255, 255, 255);
$red = imagecolorallocate($im, 255, 0, 0);

imagefilledrectangle($im,0,0,299,299,$w);

imageantialias($im,true);
imageline($im, 299, 299, 0, 299, $red);

header("Content-type: image/png");
imagepng($im);
imagedestroy($im);
?>

Expected result:
----------------
A line from bottom right corner to bottom left corner.

Actual result:
--------------
PHP Segmentation fault