Rediffed patch from Rein Klazes:winex11.drv:Add pointer check in X11DRV_SetDIBits

[Felix Nawothnig]

Louis. Lenders wrote:
> +  if( IsBadReadPtr( bits, nrsrcbytes)) return 0;

AFAIK you should never use that function since it introduces a race con. 
Try using an exception handler around the memory access itself.

Felix