Fixed bug 3992 - SDL_GetColorKey doesn't set error message

Luke A. Guest

SDL_GetColorKey does not set an error message on failure. The current source just returns -1.

The documentation https://wiki.libsdl.org/SDL_GetColorKey?highlight=%28%5CbCategoryAPI%5Cb%29%7C%28SDLFunctionTemplate%29 says to call SDL_GetError but that is useless in this case.

src/video/SDL_surface.c

@@ -296,11 +296,11 @@ int
 SDL_GetColorKey(SDL_Surface * surface, Uint32 * key)
 {
     if (!surface) {
-        return -1;
+        return SDL_InvalidParamError("surface");
     }
 
     if (!(surface->map->info.flags & SDL_COPY_COLORKEY)) {
-        return -1;
+        return SDL_SetError("Surface doesn't have a colorkey");
     }
 
     if (key) {