add ignore_placed_rotation to building def

common.lua

@@ -101,8 +101,11 @@ function building_lib.get_next_buildable_position(player, buildingname)
 		if placed_building_info then
 			-- use origin and rotation of existing pointed-at building
 			pointed_mapblock_pos = placed_building_origin
+			if not building_def.ignore_placed_rotation then
+				-- use rotation from already placed building
 				rotation = placed_building_info.rotation
 			end
+		end
 
 		if building_def then
 			local size = building_lib.get_building_size(building_def, rotation)