If an app requests a 24-bit opengl mode on a machine with a 32-bit desktop with
the windib video backend, then when exiting fullscreen the desktop resolution
is not restored

The reason this is, is because the windib backend restores the desktop
resolution when exiting fullscreen in DIB_SetVideoMode when it finds that the
last request was for fullscreen by checking the original flags on the video
surface. However, if the bits per pixel requested is different than current
surface, the video surface is recreated and the original video flags are lost.
So the check to see if we were exiting fullscreen fails.

below is a patch to SDL_dibvideo.c that solves the problem by using the
original flags in all cases.

thanks!

--HG--
branch : SDL-1.2
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/branches/SDL-1.2%402647