In ImageMagick 6.7.9-4, there are several code paths in SetImageAlphaChannel (magick/channel.c) that will always return MagickFalse. The 'status' variable that is ultimately returned is initialised to MagickFalse, but the switch cases for ActivateAlphaChannel and DeactivateAlphaChannel (for example) do not set it to MagickTrue.
If this is intentional please let me know how to detect whether there's been an exception!
MagickSetImageAlphaChannel always returns MagickFalse?
Re: MagickSetImageAlphaChannel always returns MagickFalse?
We can reproduce the problem you posted and have a patch in ImageMagick 6.8.0-4 Beta available by sometime tomorrow. Thanks.