libretro: don't dereference a NULL game info in retro_load_game

libretro.c

@@ -270,6 +270,11 @@ bool retro_load_game(const struct retro_game_info *info)
 
    enum retro_pixel_format fmt = RETRO_PIXEL_FORMAT_RGB565;
 
+   if (!info || !info->data || info->size == 0)
+   {
+      return false;
+   }
+
    if (!environ_cb(RETRO_ENVIRONMENT_SET_PIXEL_FORMAT, &fmt))
    {
       return false;
@@ -278,6 +283,10 @@ bool retro_load_game(const struct retro_game_info *info)
    check_variables();
 
    datafile_buffer = (unsigned char *) malloc(info->size);
+   if (!datafile_buffer)
+   {
+      return false;
+   }
    memcpy(datafile_buffer, info->data, info->size);
 
    init_program();
@@ -290,6 +299,7 @@ void retro_unload_game(void)
 {
    deinit_program();
    free(datafile_buffer);
+   datafile_buffer = NULL;
 }
 
 unsigned retro_get_region(void)