Bug #72913 [Asn->Csd]: imagecopy() loses single-color transparency on palette images

Edit report at https://bugs.php.net/bug.php?id=72913&edit=1 ID: 72913 Updated by: cmb@php.net Reported by: cmb@php.net Summary: imagecopy() loses single-color transparency on palette images -Status: Assigned +Status: Closed Type: Bug Package: GD related Operating System: * PHP Version: 7.0.10 Assigned To: cmb Block user comment: N Private report: N New Comment: Automatic comment on behalf of cmbecker69@gmx.de Revision: http://git.php.net/?p=php-src.git;a=commit;h=d65adac2be2c9b32d9ad9bd00399c99d492502f5 Log: Fix #72913: imagecopy() loses single-color transparency on palette images Previous Comments: ------------------------------------------------------------------------ [2016-08-21 15:26:28] cmb@php.net Description: ------------ When copying a single-color transparency true-color image onto a palette image with imagecopy(), the transparency is lost, if compiled against the bundled libgd. With external libgd it works fine. That bug affects all currently supported PHP versions. Test script: --------------- <?php $base64 = 'iVBORw0KGgoAAAANSUhEUgAAADIAAAAyCAIAAACRXR/mAAAABnRSTlMAAAAAAABu' . 'pgeRAAAAVklEQVRYw+3UQQqAMBAEwf3/p9eTBxEPiWAmWMU8oGFJqgAAuOpzWTX3' . 'xQUti+uRJTZ9V5aY1bOTFZLV7yZr9zt6ibv/qPXfrMpsGipbIy7oqQ8AYJED1plD' . 'y5PCu2sAAAAASUVORK5CYII='; $src = imagecreatefromstring(base64_decode($base64)); $dst = imagecreate(50, 50); $transparent = imagecolorallocatealpha($dst, 255, 255, 255, 127); imagealphablending($dst, false); imagesavealpha($dst, true); imagecopy($dst, $src, 0,0, 0,0, 50,50); imagepng($dst, __DIR__ . '/test.png'); Expected result: ---------------- An image with red circle on a _transparent_ background. Actual result: -------------- An image with red circle on a _black_ background. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=72913&edit=1