[GM-bugs] bug in ReadGIFImage when using local localmap

[莫红波 <hon...@up...>]

It's strange in sourceforge. Sorry for post so many mails.

Some GIFs set transparent color index equal to size of colormaps which is
an invalid value.

1011     if (opacity >= (long) image->colors)
1012       image->colors=opacity+1;

As code above, Graphicsmagick will set image->colors equal to opacity+1.
However, this is a bug when reading colormaps from image blob.

1067         if (ReadBlob(image,3*image->colors,(char *) colormap) !=
3*image->colors)

ReadBlob will read more colors which are not real color.

BTW, I can't upload GIF Image as it's too large.