silverstripe/sapphire — pull request #994 by tractorcow (2012-12-04 04:21:05+00:00)
Title: BUG GD::greyscale did not correctly preserve alpha component of images

Greyscaling of images doesn't preserve alpha component of some images.

This has been fixed, and some rigorous test cases added. These test cases fail with the unfixed code.

There's plenty of room within the GDTest to add additional test cases, for someone with more time on their hands.