Merge branch 'master' into jgrpp

# Conflicts:
#	cmake/CompileFlags.cmake
#	src/3rdparty/squirrel/squirrel/sqclosure.h
#	src/3rdparty/squirrel/squirrel/sqobject.h
#	src/3rdparty/squirrel/squirrel/sqvm.h
#	src/aircraft.h
#	src/airport_gui.cpp
#	src/blitter/32bpp_sse_func.hpp
#	src/blitter/null.hpp
#	src/bridge_gui.cpp
#	src/build_vehicle_gui.cpp
#	src/cargotype.h
#	src/cheat_gui.cpp
#	src/command.cpp
#	src/command_func.h
#	src/company_gui.cpp
#	src/console_gui.cpp
#	src/date_gui.cpp
#	src/depot_gui.cpp
#	src/dock_gui.cpp
#	src/economy.cpp
#	src/error_gui.cpp
#	src/fileio.cpp
#	src/fios.cpp
#	src/fios_gui.cpp
#	src/fontcache/spritefontcache.h
#	src/framerate_gui.cpp
#	src/game/game_text.cpp
#	src/gamelog.cpp
#	src/genworld_gui.cpp
#	src/gfx_layout_fallback.cpp
#	src/group_gui.cpp
#	src/highscore_gui.cpp
#	src/hotkeys.cpp
#	src/industry_cmd.cpp
#	src/industry_gui.cpp
#	src/landscape.cpp
#	src/main_gui.cpp
#	src/misc_cmd.cpp
#	src/misc_gui.cpp
#	src/network/core/tcp_game.cpp
#	src/network/core/udp.cpp
#	src/network/network_chat_gui.cpp
#	src/network/network_content_gui.cpp
#	src/network/network_gui.cpp
#	src/network/network_server.cpp
#	src/network/network_server.h
#	src/newgrf_airport.cpp
#	src/newgrf_airport.h
#	src/newgrf_airporttiles.cpp
#	src/newgrf_airporttiles.h
#	src/newgrf_animation_base.h
#	src/newgrf_canal.cpp
#	src/newgrf_commons.h
#	src/newgrf_config.cpp
#	src/newgrf_debug_gui.cpp
#	src/newgrf_engine.cpp
#	src/newgrf_engine.h
#	src/newgrf_generic.cpp
#	src/newgrf_gui.cpp
#	src/newgrf_house.cpp
#	src/newgrf_house.h
#	src/newgrf_industries.cpp
#	src/newgrf_industries.h
#	src/newgrf_industrytiles.cpp
#	src/newgrf_industrytiles.h
#	src/newgrf_object.cpp
#	src/newgrf_object.h
#	src/newgrf_railtype.cpp
#	src/newgrf_railtype.h
#	src/newgrf_roadstop.cpp
#	src/newgrf_roadstop.h
#	src/newgrf_roadtype.cpp
#	src/newgrf_roadtype.h
#	src/newgrf_spritegroup.cpp
#	src/newgrf_spritegroup.h
#	src/newgrf_station.cpp
#	src/newgrf_station.h
#	src/newgrf_town.cpp
#	src/newgrf_town.h
#	src/news_gui.cpp
#	src/object_gui.cpp
#	src/order_gui.cpp
#	src/os/macosx/crashlog_osx.cpp
#	src/os/unix/crashlog_unix.cpp
#	src/os/windows/crashlog_win.cpp
#	src/os/windows/win32.cpp
#	src/os/windows/win32_main.cpp
#	src/pathfinder/npf/npf.cpp
#	src/pathfinder/npf/queue.cpp
#	src/rail_cmd.cpp
#	src/rail_gui.cpp
#	src/road_gui.cpp
#	src/roadveh.h
#	src/saveload/saveload.cpp
#	src/screenshot.cpp
#	src/script/api/script_text.hpp
#	src/settings.cpp
#	src/settings_gui.cpp
#	src/settings_internal.h
#	src/settings_table.cpp
#	src/signs_cmd.cpp
#	src/signs_gui.cpp
#	src/smallmap_gui.cpp
#	src/smallmap_gui.h
#	src/spriteloader/grf.hpp
#	src/station_cmd.cpp
#	src/station_gui.cpp
#	src/station_map.h
#	src/statusbar_gui.cpp
#	src/stdafx.h
#	src/strgen/strgen.cpp
#	src/table/newgrf_debug_data.h
#	src/terraform_gui.cpp
#	src/timer/timer_game_calendar.cpp
#	src/timer/timer_window.cpp
#	src/town.h
#	src/town_cmd.cpp
#	src/town_gui.cpp
#	src/train_gui.cpp
#	src/transparency_gui.cpp
#	src/vehicle_gui.cpp
#	src/water_cmd.cpp
#	src/waypoint_cmd.cpp
#	src/widget.cpp
#	src/widget_type.h
#	src/widgets/dropdown.cpp
#	src/widgets/rail_widget.h
#	src/widgets/terraform_widget.h
#	src/window.cpp
#	src/window_gui.h

src/terraform_gui.cpp

@@ -210,7 +210,7 @@ struct TerraformToolbarWindow : Window {
 		/* This is needed as we like to have the tree available on OnInit. */
 		this->CreateNestedTree();
 		this->FinishInitNested(window_number);
-		this->last_user_action = WIDGET_LIST_END;
+		this->last_user_action = INVALID_WID_TT;
 	}
 
 	void OnInit() override
@@ -221,7 +221,7 @@ struct TerraformToolbarWindow : Window {
 		SetWidgetDisabledState(WID_TT_BUY_LAND, _settings_game.construction.purchase_land_permitted == 0);
 	}
 
-	void OnClick(Point pt, int widget, int click_count) override
+	void OnClick([[maybe_unused]] Point pt, int widget, [[maybe_unused]] int click_count) override
 	{
 		if (widget < WID_TT_BUTTONS_START) return;
 
@@ -273,7 +273,7 @@ struct TerraformToolbarWindow : Window {
 		}
 	}
 
-	void OnPlaceObject(Point pt, TileIndex tile) override
+	void OnPlaceObject([[maybe_unused]] Point pt, TileIndex tile) override
 	{
 		switch (this->last_user_action) {
 			case WID_TT_LOWER_LAND: // Lower land button
@@ -320,7 +320,7 @@ struct TerraformToolbarWindow : Window {
 		}
 	}
 
-	void OnPlaceDrag(ViewportPlaceMethod select_method, ViewportDragDropSelectionProcess select_proc, Point pt) override
+	void OnPlaceDrag(ViewportPlaceMethod select_method, [[maybe_unused]] ViewportDragDropSelectionProcess select_proc, [[maybe_unused]] Point pt) override
 	{
 		VpSelectTilesWithMethod(pt.x, pt.y, select_method);
 	}
@@ -332,7 +332,7 @@ struct TerraformToolbarWindow : Window {
 		return pt;
 	}
 
-	void OnPlaceMouseUp(ViewportPlaceMethod select_method, ViewportDragDropSelectionProcess select_proc, Point pt, TileIndex start_tile, TileIndex end_tile) override
+	void OnPlaceMouseUp([[maybe_unused]] ViewportPlaceMethod select_method, ViewportDragDropSelectionProcess select_proc, [[maybe_unused]] Point pt, TileIndex start_tile, TileIndex end_tile) override
 	{
 		if (pt.x != -1) {
 			switch (select_proc) {
@@ -576,10 +576,9 @@ static const NWidgetPart _nested_scen_edit_land_gen_widgets[] = {
 
 /**
  * Callback function for the scenario editor 'reset landscape' confirmation window
- * @param w Window unused
  * @param confirmed boolean value, true when yes was clicked, false otherwise
  */
-static void ResetLandscapeConfirmationCallback(Window *w, bool confirmed)
+static void ResetLandscapeConfirmationCallback(Window *, bool confirmed)
 {
 	if (confirmed) {
 		/* Set generating_world to true to get instant-green grass after removing
@@ -617,7 +616,7 @@ struct ScenarioEditorLandscapeGenerationWindow : Window {
 		this->CreateNestedTree();
 		this->SetButtonStates();
 		this->FinishInitNested(window_number);
-		this->last_user_action = WIDGET_LIST_END;
+		this->last_user_action = INVALID_WID_ETT;
 	}
 
 	void OnPaint() override
@@ -629,7 +628,7 @@ struct ScenarioEditorLandscapeGenerationWindow : Window {
 		}
 	}
 
-	void UpdateWidgetSize(int widget, Dimension *size, const Dimension &padding, Dimension *fill, Dimension *resize) override
+	void UpdateWidgetSize(int widget, Dimension *size, [[maybe_unused]] const Dimension &padding, [[maybe_unused]] Dimension *fill, [[maybe_unused]] Dimension *resize) override
 	{
 		if (widget != WID_ETT_DOTS) return;
 
@@ -654,7 +653,7 @@ struct ScenarioEditorLandscapeGenerationWindow : Window {
 		} while (--n);
 	}
 
-	void OnClick(Point pt, int widget, int click_count) override
+	void OnClick([[maybe_unused]] Point pt, int widget, [[maybe_unused]] int click_count) override
 	{
 		if (widget < WID_ETT_BUTTONS_START) return;
 
@@ -734,14 +733,11 @@ struct ScenarioEditorLandscapeGenerationWindow : Window {
 	{
 		for (uint i = WID_ETT_START; i < this->nested_array_size; i++) {
 			if (i == WID_ETT_BUTTONS_START) i = WID_ETT_BUTTONS_END; // skip the buttons
-			if (this->IsWidgetLowered(i)) {
-				this->RaiseWidget(i);
-				this->SetWidgetDirty(i);
-			}
+			this->RaiseWidgetWhenLowered(i);
 		}
 	}
 
-	void OnPlaceObject(Point pt, TileIndex tile) override
+	void OnPlaceObject([[maybe_unused]] Point pt, TileIndex tile) override
 	{
 		switch (this->last_user_action) {
 			case WID_ETT_DEMOLISH: // Demolish aka dynamite button
@@ -772,12 +768,12 @@ struct ScenarioEditorLandscapeGenerationWindow : Window {
 		}
 	}
 
-	void OnPlaceDrag(ViewportPlaceMethod select_method, ViewportDragDropSelectionProcess select_proc, Point pt) override
+	void OnPlaceDrag(ViewportPlaceMethod select_method, [[maybe_unused]] ViewportDragDropSelectionProcess select_proc, [[maybe_unused]] Point pt) override
 	{
 		VpSelectTilesWithMethod(pt.x, pt.y, select_method);
 	}
 
-	void OnPlaceMouseUp(ViewportPlaceMethod select_method, ViewportDragDropSelectionProcess select_proc, Point pt, TileIndex start_tile, TileIndex end_tile) override
+	void OnPlaceMouseUp([[maybe_unused]] ViewportPlaceMethod select_method, ViewportDragDropSelectionProcess select_proc, [[maybe_unused]] Point pt, TileIndex start_tile, TileIndex end_tile) override
 	{
 		if (pt.x != -1) {
 			switch (select_proc) {