fixed layout memory leak

cybersyn/changelog.txt

@@ -11,6 +11,7 @@ Date: 2022-12-23
     - Nonempty trains in depot are no longer put in manual mode, instead they are forced to park at the depot
     - Made several alerts persistent
     - Fixed bug with depot priority not working
+    - Fixed a memory leak relating to train layouts
 ---------------------------------------------------------------------------------------------------
 Version: 1.1.7
 Date: 2022-12-17

cybersyn/scripts/layout.lua

@@ -87,6 +87,19 @@ function remove_train(map_data, train_id, train)
 		depot.available_train_id = nil
 	end
 	remove_available_train(map_data, train_id, train)
+
+	local layout_id = train.layout_id
+	local count = global.layout_train_count[layout_id]
+	if count <= 1 then
+		global.layout_train_count[layout_id] = nil
+		global.layouts[layout_id] = nil
+		for _, station in pairs(global.stations) do
+			station.accepted_layouts[layout_id] = nil
+		end
+	else
+		global.layout_train_count[layout_id] = count - 1
+	end
+
 	map_data.trains[train_id] = nil
 	interface_raise_train_removed(train_id, train)
 end

cybersyn/scripts/migrations.lua

@@ -135,7 +135,20 @@ local migrations_table = {
 			control.parameters = params
 		end
 		for id, station in pairs(map_data.stations) do
-			station.display_state = (station.display_state >= 2 and 1) + (station.display_state%2)*2
+			station.display_state = (station.display_state >= 2 and 1 or 0) + (station.display_state%2)*2
+		end
+
+		map_data.layout_train_count = {}
+		for id, train in pairs(map_data.trains) do
+			map_data.layout_train_count[train.layout_id] = (map_data.layout_train_count[train.layout_id] or 0) + 1
+		end
+		for layout_id, _ in pairs(map_data.layouts) do
+			if not map_data.layout_train_count[layout_id] then
+				map_data.layouts[layout_id] = nil
+				for id, station in pairs(map_data.stations) do
+					station.accepted_layouts[layout_id] = nil
+				end
+			end
 		end
 	end,
 }