if a GOImage was created using go_image_new_from_pixbuf it may not have a name. In that case gog_styled_object_document_changed will crash at:

		char *id = g_strdup (go_image_get_name (style->fill.image.image));
		/* remove the (nnn) modifier if any */
		int i = strlen (id) - 1;

since strlen does not like a NULL argument!