Fixed crash:

#include <SDL.h>

int main(int argc, char** argv)
{
        SDL_Init(SDL_INIT_EVERYTHING);
        SDL_SetVideoMode(640, 480, 0, SDL_FULLSCREEN);
        SDL_ShowCursor(SDL_DISABLE);
        SDL_Delay(1000);
        SDL_SetVideoMode(640, 480, 0, SDL_FULLSCREEN | SDL_OPENGL);
        SDL_Quit();
        printf("Everything okay\n");
}

src/video/SDL_video.c

@@ -643,6 +643,7 @@ SDL_Surface * SDL_SetVideoMode (int width, int height, int bpp, Uint32 flags)
 	/* Reset the keyboard here so event callbacks can run */
 	SDL_ResetKeyboard();
 	SDL_ResetMouse();
+	SDL_cursorstate &= ~CURSOR_USINGSW;
 
 	/* Clean up any previous video mode */
 	if ( SDL_PublicSurface != NULL ) {