Having updated GD-Library from 2.0.35-r1 to 2.0.35-r3 using negative numbers for $dstX or $dstY started to produce unpredictable results, such as inserting shrinked images and enlarging $dstH or $dstW all by itself. While it did work fine previously, one should avoid using or calculating negative numbers for imagecopyresampled from the beginning.