[3/5] windowscodecs: Create a predefined black&white palette if 1 bpp TIFF image doesn't have one.

[Dmitry Timoshkov]

Vincent Povirk <madewokherd at gmail.com> wrote:

> Are you sure about this? My understanding is that the result of
> CopyPalette is unspecified when your pixel format is not an indexed
> color format (in this case, a grayscale format).

It seems that WIC always creates a predefined palette if an image doesn't
have one, see the test sent in 2/5.

> So, while it's not really a problem to do that (unless a program
> relies on the exact behavior of this decoder, which seems unlikely),
> for correctness you shouldn't ever be relying on this change.

The problem is that gdiplus always expects a palette when converting
between formats and crashes if there is no one.

-- 
Dmitry.