Description:
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I use imagefill to fill a picture, but no matter what I enter as start x and y, it always fills the whole image (with x and y higher then 0 and not higher then image sizes)

Reproduce code:
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header("Content-Type: image/png");
$img	= imagecreatetruecolor(100,100);
$red	= imagecolorallocate($img,255,0,0);
$green	= imagecolorallocate($img,0,255,0);
imagefill($img,0,0,$red);
imagefill($img,50,0,$green);
imagepng($img);

Expected result:
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A picture, 100 x 100, with the left half red and the right half green

Actual result:
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A picture, 100 x 100, completely green