[image] Clear LOADED flag on all other images when loading a new image

Loading an image may overwrite part or all of any previously-loaded
images, so we should clear the LOADED flag for all images prior to
attempting to load a new image.

src/core/image.c

 struct image * find_image ( const char *name ) {
 	struct image *image;
 
-	list_for_each_entry ( image, &images, list ) {
+	for_each_image ( image ) {
 		if ( strcmp ( image->name, name ) == 0 )
 			return image;
 	}
  * @ret rc		Return status code
  */
 static int image_load_type ( struct image *image, struct image_type *type ) {
+	struct image *tmp_image;
 	int rc;
 
 	/* Check image is actually loadable */
 	if ( ! type->load )
 		return -ENOEXEC;
 
+	/* Clear the loaded flag on all images; loading this image
+	 * will invalidate any previous loads.  (Even if loading
+	 * fails, the previously loaded image may still have been
+	 * partially overwritten.)
+	 */
+	for_each_image ( tmp_image )
+		tmp_image->flags &= ~IMAGE_LOADED;
+
 	/* Try the image loader */
 	if ( ( rc = type->load ( image ) ) != 0 ) {
 		DBGC ( image, "IMAGE %p could not load as %s: %s\n",