Fixes level order

mods/persistence/controllers/subsystems/persistence.dm

@@ -376,42 +376,55 @@
 		loading_world = TRUE
 
 		// Start with rebuilding the z-levels.
-		//var/last_index = world.maxz
+
 		var/list/unmapped_z     = list()
 		var/list/mapped_z       = list()
 		var/list/mapped_indices = list() //Indices reserved by mapped zlevels
 
+		var/min_mapped_index
+		var/mapped_offset = 0
 		///Sort z-levels on whether they got a mapped z indice, or not
 		for(var/datum/persistence/load_cache/z_level/z_level in serializer.resolver.z_levels)
 			if(z_level.dynamic)
 				unmapped_z |= z_level
 			else
 				mapped_z |= z_level
-				mapped_indices |= z_level.index
+				mapped_indices[num2text(z_level.index)] = z_level.level_data_subtype
+
+				if(!min_mapped_index || z_level.index < min_mapped_index)
+					min_mapped_index = z_level.index
+
+		// If mapping changes have resulted in more levels existing then during save, offset the mapped levels.
+		mapped_offset = max(0, world.maxz + 1 - min_mapped_index)
 
 		//Then handle assigning z levels
 		for(var/datum/persistence/load_cache/z_level/z_level in mapped_z)
 			//If the world z isn't at the index we're loading this level at, increment
-			for(var/z_incr = 1 to  max(z_level.index - world.maxz, 0))
-				// Always init to space new levels. It really doesn't matter
-				SSmapping.increment_world_z_size(text2path("[z_level.level_data_subtype]") || /datum/level_data/space, TRUE)
-				//If we have any unmapped z levels to place, use the empty space between
-				if(length(unmapped_z) && !(world.maxz in mapped_indices))
-					var/datum/persistence/load_cache/z_level/unmapped = unmapped_z[unmapped_z.len]
-					unmapped_z.len--
-					unmapped.new_index = world.maxz
-					serializer.z_map["[unmapped.index]"] = unmapped.new_index
-					report_progress_serializer("Mapping Save Z ([unmapped.index]) to World Z ([unmapped.new_index]) with default turf ([unmapped.default_turf]).")
+			z_level.new_index = z_level.index + mapped_offset
+			for(var/z_incr = 1 to max(z_level.new_index - world.maxz, 0))
 
-			report_progress_serializer("Mapping Save Z ([z_level.index]) to World Z ([z_level.new_index]) with default turf ([z_level.default_turf]).")
-			z_level.new_index = z_level.index
+				// map_indices is indexed by the database value, so we need to re-adjust.
+				var/index_key = num2text(world.maxz - mapped_offset)
+				if(index_key in mapped_indices)
+					SSmapping.increment_world_z_size(text2path(mapped_indices[index_key]) || /datum/level_data/space, TRUE)
+				else
+					SSmapping.increment_world_z_size(/datum/level_data/space, TRUE)
+					//If we have any unmapped z levels to place, use the empty space between
+					if(length(unmapped_z))
+						var/datum/persistence/load_cache/z_level/unmapped = unmapped_z[unmapped_z.len]
+						unmapped_z.len--
+						unmapped.new_index = world.maxz
+						serializer.z_map["[unmapped.index]"] = unmapped.new_index
+						report_progress_serializer("Mapping Save Z ([unmapped.index]) to World Z ([unmapped.new_index]) with default turf ([unmapped.default_turf]).")
+
+			report_progress_serializer("Mapping Save Z ([z_level.index]) to World Z ([z_level.new_index]) with default turf ([z_level.default_turf]) and level data [z_level.level_data_subtype].")
 			serializer.z_map[num2text(z_level.index)] = z_level.new_index
 
 		//If any unmapped left, add them
 		for(var/datum/persistence/load_cache/z_level/z_level in unmapped_z)
 			SSmapping.increment_world_z_size(/datum/level_data/space)
 			z_level.new_index = world.maxz
-			serializer.z_map["[z_level.index]"] = z_level.new_index
+			serializer.z_map[num2text(z_level.index)] = z_level.new_index
 			report_progress_serializer("Mapping Save Z ([z_level.index]) to World Z ([z_level.new_index]) with default turf ([z_level.default_turf]).")
 		report_progress_serializer("Z-Levels loaded!")
 

mods/persistence/modules/world_save/serializers/sql_serializer.dm

@@ -628,6 +628,7 @@ var/global/list/serialization_time_spent_type
 		var/datum/persistence/load_cache/z_level/z_level = z_transform[z]
 		z_inserts += "([z_insert_index],[z_level.new_index],[z_level.dynamic],'[z_level.default_turf]','[z_level.metadata]','[json_encode(z_level.areas)]','[z_level.level_data_subtype]')"
 		z_insert_index++
+
 	var/DBQuery/query = dbcon_save.NewQuery("INSERT INTO `[SQLS_TABLE_Z_LEVELS]` (`id`,`z`,`dynamic`,`default_turf`,`metadata`,`areas`,`level_data_subtype`) VALUES[jointext(z_inserts, ",")]")
 	SQLS_EXECUTE_AND_REPORT_ERROR(query, "Z_LEVEL SERIALIZATION FAILED:")
 	return TRUE

mods/persistence/modules/world_save/wrappers/map_data_wrapper.dm

@@ -13,10 +13,14 @@
 	var/turf/T = get_turf(M)
 	height = M.height
 	landmark_loc = "[T.x],[T.y],[T.z]"
-	
+
 /datum/wrapper/map_data/on_deserialize(var/serializer/curr_serializer)
 	var/list/coords = splittext(landmark_loc, ",")
 	report_progress_serializer("Deserialized map data on z [text2num(coords[3])]")
-	var/turf/T = locate(text2num(coords[1]), text2num(coords[2]), text2num(coords[3]))
+
+	var/adjusted_z = text2num(coords[3])
+	if(curr_serializer.z_map[num2text(adjusted_z)])
+		adjusted_z = curr_serializer.z_map[num2text(adjusted_z)]
+
+	var/turf/T = locate(text2num(coords[1]), text2num(coords[2]), adjusted_z)
 	return new /obj/abstract/map_data(T, text2num(height))
-