A day for bug fixing

Yesterday I had a full day with only bug fixing. Some notes:

gcc optimizes away nil checks of functions in some cases. Bad if you weak link this function.
In PictureMBS is forgot to handle alpha channel in RowInFormat for RGBA to RGBA. More than 30 different code branches and in this one, I forgot it.
For CGBitmapContext Mac OS X 10.3 and newer can allocate memory for you. But you have to allocate it yourself if you later want to access it. Sadly this is not documented.
Our CombinePictureWithMask function (used in PNG, Tiff and GraphicsMagick) got an optimization some months ago. Turns out to crash sometimes.
PictureMBS.Invert did not work for all color configurations. Fixed now.
And searched a bug in IconFamilyMBS.GetIconImage, but that was just a documentation bug.
Strange, you can link to a framework function without linking to the framework. The function will be nil and calling it crashes. Linking also the framework and it works.