Codechange: do not hide variables with other variables

src/3rdparty/squirrel/squirrel/sqobject.cpp

@@ -446,11 +446,11 @@ bool SQFunctionProto::Load(SQVM *v,SQUserPointer up,SQREADFUNC read,SQObjectPtr
 
 	for(i = 0; i < noutervalues; i++){
 		SQUnsignedInteger type;
-		SQObjectPtr name;
+		SQObjectPtr value_name;
 		_CHECK_IO(SafeRead(v,read,up, &type, sizeof(SQUnsignedInteger)));
 		_CHECK_IO(ReadObject(v, up, read, o));
-		_CHECK_IO(ReadObject(v, up, read, name));
-		f->_outervalues[i] = SQOuterVar(name,o, (SQOuterType)type);
+		_CHECK_IO(ReadObject(v, up, read, value_name));
+		f->_outervalues[i] = SQOuterVar(value_name,o, (SQOuterType)type);
 	}
 	_CHECK_IO(CheckTag(v,read,up,SQ_CLOSURESTREAM_PART));
 

src/autoreplace_cmd.cpp

@@ -781,7 +781,6 @@ CommandCost CmdAutoreplaceVehicle(DoCommandFlag flags, VehicleID veh_id)
 		RestoreRandomSeeds(saved_seeds);
 
 		if (cost.Succeeded() && (flags & DC_EXEC) != 0) {
-			CommandCost ret;
 			if (free_wagon) {
 				ret = ReplaceFreeUnit(&v, flags, &nothing_to_do);
 			} else {

src/base_media_func.h

@@ -48,7 +48,7 @@ bool BaseSet<T, Tnum_files, Tsearch_in_tars>::FillSetDetails(IniFile *ini, const
 	this->description[std::string{}] = *item->value;
 
 	/* Add the translations of the descriptions too. */
-	for (const IniItem *item = metadata->item; item != nullptr; item = item->next) {
+	for (item = metadata->item; item != nullptr; item = item->next) {
 		if (item->name.compare(0, 12, "description.") != 0) continue;
 
 		this->description[item->name.substr(12)] = item->value.value_or("");

src/company_gui.cpp

@@ -633,7 +633,6 @@ private:
 	void ShowColourDropDownMenu(uint32 widget)
 	{
 		uint32 used_colours = 0;
-		const Company *c;
 		const Livery *livery, *default_livery = nullptr;
 		bool primary = widget == WID_SCL_PRI_COL_DROPDOWN;
 		byte default_col = 0;
@@ -645,7 +644,7 @@ private:
 			}
 		}
 
-		c = Company::Get((CompanyID)this->window_number);
+		const Company *c = Company::Get((CompanyID)this->window_number);
 
 		if (this->livery_class < LC_GROUP_RAIL) {
 			/* Get the first selected livery to use as the default dropdown item */

src/gfx.cpp

@@ -1327,7 +1327,6 @@ void DoPaletteAnimations()
 	const ExtraPaletteValues *ev = &_extra_palette_values;
 	Colour old_val[PALETTE_ANIM_SIZE];
 	const uint old_tc = palette_animation_counter;
-	uint i;
 	uint j;
 
 	if (blitter != nullptr && blitter->UsePaletteAnimation() == Blitter::PALETTE_ANIMATION_NONE) {
@@ -1342,7 +1341,7 @@ void DoPaletteAnimations()
 	/* Fizzy Drink bubbles animation */
 	s = ev->fizzy_drink;
 	j = EXTR2(512, EPV_CYCLES_FIZZY_DRINK);
-	for (i = 0; i != EPV_CYCLES_FIZZY_DRINK; i++) {
+	for (uint i = 0; i != EPV_CYCLES_FIZZY_DRINK; i++) {
 		*palette_pos++ = s[j];
 		j++;
 		if (j == EPV_CYCLES_FIZZY_DRINK) j = 0;
@@ -1351,7 +1350,7 @@ void DoPaletteAnimations()
 	/* Oil refinery fire animation */
 	s = ev->oil_refinery;
 	j = EXTR2(512, EPV_CYCLES_OIL_REFINERY);
-	for (i = 0; i != EPV_CYCLES_OIL_REFINERY; i++) {
+	for (uint i = 0; i != EPV_CYCLES_OIL_REFINERY; i++) {
 		*palette_pos++ = s[j];
 		j++;
 		if (j == EPV_CYCLES_OIL_REFINERY) j = 0;
@@ -1391,7 +1390,7 @@ void DoPaletteAnimations()
 	/* Handle lighthouse and stadium animation */
 	s = ev->lighthouse;
 	j = EXTR(256, EPV_CYCLES_LIGHTHOUSE);
-	for (i = 0; i != EPV_CYCLES_LIGHTHOUSE; i++) {
+	for (uint i = 0; i != EPV_CYCLES_LIGHTHOUSE; i++) {
 		*palette_pos++ = s[j];
 		j++;
 		if (j == EPV_CYCLES_LIGHTHOUSE) j = 0;
@@ -1400,7 +1399,7 @@ void DoPaletteAnimations()
 	/* Dark blue water */
 	s = (_settings_game.game_creation.landscape == LT_TOYLAND) ? ev->dark_water_toyland : ev->dark_water;
 	j = EXTR(320, EPV_CYCLES_DARK_WATER);
-	for (i = 0; i != EPV_CYCLES_DARK_WATER; i++) {
+	for (uint i = 0; i != EPV_CYCLES_DARK_WATER; i++) {
 		*palette_pos++ = s[j];
 		j++;
 		if (j == EPV_CYCLES_DARK_WATER) j = 0;
@@ -1409,7 +1408,7 @@ void DoPaletteAnimations()
 	/* Glittery water */
 	s = (_settings_game.game_creation.landscape == LT_TOYLAND) ? ev->glitter_water_toyland : ev->glitter_water;
 	j = EXTR(128, EPV_CYCLES_GLITTER_WATER);
-	for (i = 0; i != EPV_CYCLES_GLITTER_WATER / 3; i++) {
+	for (uint i = 0; i != EPV_CYCLES_GLITTER_WATER / 3; i++) {
 		*palette_pos++ = s[j];
 		j += 3;
 		if (j >= EPV_CYCLES_GLITTER_WATER) j -= EPV_CYCLES_GLITTER_WATER;
@@ -1669,23 +1668,23 @@ void DrawDirtyBlocks()
 
 				while (right != w) {
 					byte *p2 = ++p;
-					int h = h2;
+					int i = h2;
 					/* Check if a full line of dirty flags is set. */
 					do {
 						if (!*p2) goto no_more_coalesc;
 						p2 += _dirty_bytes_per_line;
-					} while (--h != 0);
+					} while (--i != 0);
 
 					/* Wohoo, can combine it one step to the right!
 					 * Do that, and clear the bits. */
 					right += DIRTY_BLOCK_WIDTH;
 
-					h = h2;
+					i = h2;
 					p2 = p;
 					do {
 						*p2 = 0;
 						p2 += _dirty_bytes_per_line;
-					} while (--h != 0);
+					} while (--i != 0);
 				}
 				no_more_coalesc:
 

src/industry_cmd.cpp

@@ -662,8 +662,6 @@ static void AnimateTile_Industry(TileIndex tile)
 	case GFX_PLASTIC_FOUNTAIN_ANIMATED_5: case GFX_PLASTIC_FOUNTAIN_ANIMATED_6:
 	case GFX_PLASTIC_FOUNTAIN_ANIMATED_7: case GFX_PLASTIC_FOUNTAIN_ANIMATED_8:
 		if ((_tick_counter & 3) == 0) {
-			IndustryGfx gfx = GetIndustryGfx(tile);
-
 			gfx = (gfx < 155) ? gfx + 1 : 148;
 			SetIndustryGfx(tile, gfx);
 			MarkTileDirtyByTile(tile);
@@ -675,8 +673,6 @@ static void AnimateTile_Industry(TileIndex tile)
 	case GFX_OILWELL_ANIMATED_3:
 		if ((_tick_counter & 7) == 0) {
 			bool b = Chance16(1, 7);
-			IndustryGfx gfx = GetIndustryGfx(tile);
-
 			byte m = GetAnimationFrame(tile) + 1;
 			if (m == 4 && (m = 0, ++gfx) == GFX_OILWELL_ANIMATED_3 + 1 && (gfx = GFX_OILWELL_ANIMATED_1, b)) {
 				SetIndustryGfx(tile, GFX_OILWELL_NOT_ANIMATED);
@@ -1467,13 +1463,13 @@ static CommandCost CheckIfIndustryTilesAreFree(TileIndex tile, const IndustryTil
 
 				/* Clear the tiles as OWNER_TOWN to not affect town rating, and to not clear protected buildings */
 				Backup<CompanyID> cur_company(_current_company, OWNER_TOWN, FILE_LINE);
-				CommandCost ret = Command<CMD_LANDSCAPE_CLEAR>::Do(DC_NONE, cur_tile);
+				ret = Command<CMD_LANDSCAPE_CLEAR>::Do(DC_NONE, cur_tile);
 				cur_company.Restore();
 
 				if (ret.Failed()) return ret;
 			} else {
 				/* Clear the tiles, but do not affect town ratings */
-				CommandCost ret = Command<CMD_LANDSCAPE_CLEAR>::Do(DC_AUTO | DC_NO_TEST_TOWN_RATING | DC_NO_MODIFY_TOWN_RATING, cur_tile);
+				ret = Command<CMD_LANDSCAPE_CLEAR>::Do(DC_AUTO | DC_NO_TEST_TOWN_RATING | DC_NO_MODIFY_TOWN_RATING, cur_tile);
 				if (ret.Failed()) return ret;
 			}
 		}

src/industry_gui.cpp

@@ -2775,7 +2775,7 @@ struct IndustryCargoesWindow : public Window {
 		int num_cust = CountMatchingAcceptingIndustries(central_sp->produced_cargo, lengthof(central_sp->produced_cargo)) + houses_accept;
 		int num_indrows = std::max(3, std::max(num_supp, num_cust)); // One is needed for the 'it' industry, and 2 for the cargo labels.
 		for (int i = 0; i < num_indrows; i++) {
-			CargoesRow &row = this->fields.emplace_back();
+			row = this->fields.emplace_back();
 			row.columns[0].MakeEmpty(CFT_EMPTY);
 			row.columns[1].MakeCargo(central_sp->accepts_cargo, lengthof(central_sp->accepts_cargo));
 			row.columns[2].MakeEmpty(CFT_EMPTY);
@@ -2850,7 +2850,7 @@ struct IndustryCargoesWindow : public Window {
 		int num_cust = CountMatchingAcceptingIndustries(&cid, 1) + houses_accept;
 		int num_indrows = std::max(num_supp, num_cust);
 		for (int i = 0; i < num_indrows; i++) {
-			CargoesRow &row = this->fields.emplace_back();
+			row = this->fields.emplace_back();
 			row.columns[0].MakeEmpty(CFT_EMPTY);
 			row.columns[1].MakeCargo(&cid, 1);
 			row.columns[2].MakeEmpty(CFT_EMPTY);

src/network/network_content.cpp

@@ -1054,11 +1054,11 @@ void ClientNetworkContentSocketHandler::CheckDependencyState(ContentInfo *ci)
 		 * After that's done run over them once again to test their children
 		 * to unselect. Don't do it immediately because it'll do exactly what
 		 * we're doing now. */
-		for (const ContentInfo *c : parents) {
-			if (c->state == ContentInfo::AUTOSELECTED) this->Unselect(c->id);
+		for (const ContentInfo *parent : parents) {
+			if (parent->state == ContentInfo::AUTOSELECTED) this->Unselect(parent->id);
 		}
-		for (const ContentInfo *c : parents) {
-			this->CheckDependencyState(this->GetContent(c->id));
+		for (const ContentInfo *parent : parents) {
+			this->CheckDependencyState(this->GetContent(parent->id));
 		}
 	}
 }

src/newgrf.cpp

@@ -4270,13 +4270,13 @@ static ChangeInfoResult RailTypeChangeInfo(uint id, int numinfo, int prop, ByteR
 				int n = buf->ReadByte();
 				for (int j = 0; j != n; j++) {
 					RailTypeLabel label = buf->ReadDWord();
-					RailType rt = GetRailTypeByLabel(BSWAP32(label), false);
-					if (rt != INVALID_RAILTYPE) {
+					RailType resolved_rt = GetRailTypeByLabel(BSWAP32(label), false);
+					if (resolved_rt != INVALID_RAILTYPE) {
 						switch (prop) {
-							case 0x0F: SetBit(rti->powered_railtypes, rt);               FALLTHROUGH; // Powered implies compatible.
-							case 0x0E: SetBit(rti->compatible_railtypes, rt);            break;
-							case 0x18: SetBit(rti->introduction_required_railtypes, rt); break;
-							case 0x19: SetBit(rti->introduces_railtypes, rt);            break;
+							case 0x0F: SetBit(rti->powered_railtypes, resolved_rt);               FALLTHROUGH; // Powered implies compatible.
+							case 0x0E: SetBit(rti->compatible_railtypes, resolved_rt);            break;
+							case 0x18: SetBit(rti->introduction_required_railtypes, resolved_rt); break;
+							case 0x19: SetBit(rti->introduces_railtypes, resolved_rt);            break;
 						}
 					}
 				}
@@ -4484,12 +4484,12 @@ static ChangeInfoResult RoadTypeChangeInfo(uint id, int numinfo, int prop, ByteR
 				int n = buf->ReadByte();
 				for (int j = 0; j != n; j++) {
 					RoadTypeLabel label = buf->ReadDWord();
-					RoadType rt = GetRoadTypeByLabel(BSWAP32(label), false);
-					if (rt != INVALID_ROADTYPE) {
+					RoadType resolved_rt = GetRoadTypeByLabel(BSWAP32(label), false);
+					if (resolved_rt != INVALID_ROADTYPE) {
 						switch (prop) {
-							case 0x0F: SetBit(rti->powered_roadtypes, rt);               break;
-							case 0x18: SetBit(rti->introduction_required_roadtypes, rt); break;
-							case 0x19: SetBit(rti->introduces_roadtypes, rt);            break;
+							case 0x0F: SetBit(rti->powered_roadtypes, resolved_rt);               break;
+							case 0x18: SetBit(rti->introduction_required_roadtypes, resolved_rt); break;
+							case 0x19: SetBit(rti->introduces_roadtypes, resolved_rt);            break;
 						}
 					}
 				}

src/newgrf_gui.cpp

@@ -1285,16 +1285,16 @@ struct NewGRFWindow : public Window, NewGRFScanCallback {
 			WIDGET_LIST_END
 		);
 
-		const GRFConfig *c = (this->avail_sel == nullptr) ? this->active_sel : this->avail_sel;
+		const GRFConfig *selected_config = (this->avail_sel == nullptr) ? this->active_sel : this->avail_sel;
 		for (TextfileType tft = TFT_BEGIN; tft < TFT_END; tft++) {
-			this->SetWidgetDisabledState(WID_NS_NEWGRF_TEXTFILE + tft, c == nullptr || c->GetTextfile(tft) == nullptr);
+			this->SetWidgetDisabledState(WID_NS_NEWGRF_TEXTFILE + tft, selected_config == nullptr || selected_config->GetTextfile(tft) == nullptr);
 		}
-		this->SetWidgetDisabledState(WID_NS_OPEN_URL, c == nullptr || StrEmpty(c->GetURL()));
+		this->SetWidgetDisabledState(WID_NS_OPEN_URL, selected_config == nullptr || StrEmpty(selected_config->GetURL()));
 
 		this->SetWidgetDisabledState(WID_NS_SET_PARAMETERS, !this->show_params || this->active_sel == nullptr || this->active_sel->num_valid_params == 0);
 		this->SetWidgetDisabledState(WID_NS_VIEW_PARAMETERS, !this->show_params || this->active_sel == nullptr || this->active_sel->num_valid_params == 0);
 		this->SetWidgetDisabledState(WID_NS_TOGGLE_PALETTE, disable_all ||
-				(!(_settings_client.gui.newgrf_developer_tools || _settings_client.gui.scenario_developer) && ((c->palette & GRFP_GRF_MASK) != GRFP_GRF_UNSET)));
+				(!(_settings_client.gui.newgrf_developer_tools || _settings_client.gui.scenario_developer) && ((selected_config->palette & GRFP_GRF_MASK) != GRFP_GRF_UNSET)));
 
 		if (!disable_all) {
 			/* All widgets are now enabled, so disable widgets we can't use */

src/openttd.cpp

@@ -1403,7 +1403,7 @@ void StateGameLoop()
 
 #ifndef DEBUG_DUMP_COMMANDS
 		{
-			PerformanceMeasurer framerate(PFE_ALLSCRIPTS);
+			PerformanceMeasurer script_framerate(PFE_ALLSCRIPTS);
 			AI::GameLoop();
 			Game::GameLoop();
 		}

src/order_cmd.cpp

@@ -754,7 +754,7 @@ CommandCost CmdInsertOrder(DoCommandFlag flags, VehicleID veh, VehicleOrderID se
 			if (st == nullptr) return CMD_ERROR;
 
 			if (st->owner != OWNER_NONE) {
-				CommandCost ret = CheckOwnership(st->owner);
+				ret = CheckOwnership(st->owner);
 				if (ret.Failed()) return ret;
 			}
 
@@ -800,7 +800,7 @@ CommandCost CmdInsertOrder(DoCommandFlag flags, VehicleID veh, VehicleOrderID se
 
 					if (st == nullptr) return CMD_ERROR;
 
-					CommandCost ret = CheckOwnership(st->owner);
+					ret = CheckOwnership(st->owner);
 					if (ret.Failed()) return ret;
 
 					if (!CanVehicleUseStation(v, st) || !st->airport.HasHangar()) {
@@ -811,7 +811,7 @@ CommandCost CmdInsertOrder(DoCommandFlag flags, VehicleID veh, VehicleOrderID se
 
 					if (dp == nullptr) return CMD_ERROR;
 
-					CommandCost ret = CheckOwnership(GetTileOwner(dp->xy));
+					ret = CheckOwnership(GetTileOwner(dp->xy));
 					if (ret.Failed()) return ret;
 
 					switch (v->type) {
@@ -849,7 +849,7 @@ CommandCost CmdInsertOrder(DoCommandFlag flags, VehicleID veh, VehicleOrderID se
 				case VEH_TRAIN: {
 					if (!(wp->facilities & FACIL_TRAIN)) return_cmd_error(STR_ERROR_CAN_T_ADD_ORDER);
 
-					CommandCost ret = CheckOwnership(wp->owner);
+					ret = CheckOwnership(wp->owner);
 					if (ret.Failed()) return ret;
 					break;
 				}
@@ -857,7 +857,7 @@ CommandCost CmdInsertOrder(DoCommandFlag flags, VehicleID veh, VehicleOrderID se
 				case VEH_SHIP:
 					if (!(wp->facilities & FACIL_DOCK)) return_cmd_error(STR_ERROR_CAN_T_ADD_ORDER);
 					if (wp->owner != OWNER_NONE) {
-						CommandCost ret = CheckOwnership(wp->owner);
+						ret = CheckOwnership(wp->owner);
 						if (ret.Failed()) return ret;
 					}
 					break;
@@ -1514,7 +1514,7 @@ CommandCost CmdCloneOrder(DoCommandFlag flags, CloneOptions action, VehicleID ve
 			/* Sanity checks */
 			if (src == nullptr || !src->IsPrimaryVehicle() || dst->type != src->type || dst == src) return CMD_ERROR;
 
-			CommandCost ret = CheckOwnership(src->owner);
+			ret = CheckOwnership(src->owner);
 			if (ret.Failed()) return ret;
 
 			/* Trucks can't share orders with busses (and visa versa) */
@@ -1571,7 +1571,7 @@ CommandCost CmdCloneOrder(DoCommandFlag flags, CloneOptions action, VehicleID ve
 			/* Sanity checks */
 			if (src == nullptr || !src->IsPrimaryVehicle() || dst->type != src->type || dst == src) return CMD_ERROR;
 
-			CommandCost ret = CheckOwnership(src->owner);
+			ret = CheckOwnership(src->owner);
 			if (ret.Failed()) return ret;
 
 			/* Trucks can't copy all the orders from busses (and visa versa),
@@ -1771,12 +1771,9 @@ void RemoveOrderFromAllVehicles(OrderType type, DestinationID destination, bool
 
 	/* Go through all vehicles */
 	for (Vehicle *v : Vehicle::Iterate()) {
-		Order *order;
-
-		order = &v->current_order;
-		if ((v->type == VEH_AIRCRAFT && order->IsType(OT_GOTO_DEPOT) && !hangar ? OT_GOTO_STATION : order->GetType()) == type &&
+		if ((v->type == VEH_AIRCRAFT && v->current_order.IsType(OT_GOTO_DEPOT) && !hangar ? OT_GOTO_STATION : v->current_order.GetType()) == type &&
 				(!hangar || v->type == VEH_AIRCRAFT) && v->current_order.GetDestination() == destination) {
-			order->MakeDummy();
+			v->current_order.MakeDummy();
 			SetWindowDirty(WC_VEHICLE_VIEW, v->index);
 		}
 

src/rail_cmd.cpp

@@ -531,7 +531,7 @@ CommandCost CmdBuildSingleRail(DoCommandFlag flags, TileIndex tile, RailType rai
 					/* Disallow breaking end-of-line of someone else
 					 * so trams can still reverse on this tile. */
 					if (Company::IsValidID(tram_owner) && HasExactlyOneBit(tram)) {
-						CommandCost ret = CheckOwnership(tram_owner);
+						ret = CheckOwnership(tram_owner);
 						if (ret.Failed()) return ret;
 					}
 
@@ -893,7 +893,7 @@ static CommandCost CmdRailTrackHelper(DoCommandFlag flags, TileIndex tile, TileI
 	bool had_success = false;
 	CommandCost last_error = CMD_ERROR;
 	for (;;) {
-		CommandCost ret = remove ? Command<CMD_REMOVE_SINGLE_RAIL>::Do(flags, tile, TrackdirToTrack(trackdir)) : Command<CMD_BUILD_SINGLE_RAIL>::Do(flags, tile, railtype, TrackdirToTrack(trackdir), auto_remove_signals);
+		ret = remove ? Command<CMD_REMOVE_SINGLE_RAIL>::Do(flags, tile, TrackdirToTrack(trackdir)) : Command<CMD_BUILD_SINGLE_RAIL>::Do(flags, tile, railtype, TrackdirToTrack(trackdir), auto_remove_signals);
 
 		if (ret.Failed()) {
 			last_error = ret;
@@ -1591,7 +1591,7 @@ CommandCost CmdConvertRail(DoCommandFlag flags, TileIndex tile, TileIndex area_s
 		 * Tunnels and bridges have special check later */
 		if (tt != MP_TUNNELBRIDGE) {
 			if (!IsCompatibleRail(type, totype)) {
-				CommandCost ret = IsPlainRailTile(tile) ? EnsureNoTrainOnTrackBits(tile, GetTrackBits(tile)) : EnsureNoVehicleOnGround(tile);
+				ret = IsPlainRailTile(tile) ? EnsureNoTrainOnTrackBits(tile, GetTrackBits(tile)) : EnsureNoVehicleOnGround(tile);
 				if (ret.Failed()) {
 					error = ret;
 					continue;
@@ -1675,7 +1675,7 @@ CommandCost CmdConvertRail(DoCommandFlag flags, TileIndex tile, TileIndex area_s
 
 				/* When not converting rail <-> el. rail, any vehicle cannot be in tunnel/bridge */
 				if (!IsCompatibleRail(GetRailType(tile), totype)) {
-					CommandCost ret = TunnelBridgeIsFree(tile, endtile);
+					ret = TunnelBridgeIsFree(tile, endtile);
 					if (ret.Failed()) {
 						error = ret;
 						continue;

src/road_cmd.cpp

@@ -865,7 +865,7 @@ do_clear:;
 				if (HasPowerOnRoad(rt, existing_rt)) {
 					rt = existing_rt;
 				} else if (HasPowerOnRoad(existing_rt, rt)) {
-					CommandCost ret = Command<CMD_CONVERT_ROAD>::Do(flags, tile, tile, rt);
+					ret = Command<CMD_CONVERT_ROAD>::Do(flags, tile, tile, rt);
 					if (ret.Failed()) return ret;
 					cost.AddCost(ret);
 				} else {
@@ -1715,7 +1715,7 @@ static void DrawTile_Road(TileInfo *ti)
 			/* Draw rail/PBS overlay */
 			bool draw_pbs = _game_mode != GM_MENU && _settings_client.gui.show_track_reservation && HasCrossingReservation(ti->tile);
 			if (rti->UsesOverlay()) {
-				PaletteID pal = draw_pbs ? PALETTE_CRASH : PAL_NONE;
+				pal = draw_pbs ? PALETTE_CRASH : PAL_NONE;
 				SpriteID rail = GetCustomRailSprite(rti, ti->tile, RTSG_CROSSING) + axis;
 				DrawGroundSprite(rail, pal);
 
@@ -1757,7 +1757,7 @@ static void DrawTile_Road(TileInfo *ti)
 				}
 			} else if (draw_pbs || tram_rti != nullptr || road_rti->UsesOverlay()) {
 				/* Add another rail overlay, unless there is only the base road sprite. */
-				PaletteID pal = draw_pbs ? PALETTE_CRASH : PAL_NONE;
+				pal = draw_pbs ? PALETTE_CRASH : PAL_NONE;
 				SpriteID rail = GetCrossingRoadAxis(ti->tile) == AXIS_Y ? GetRailTypeInfo(GetRailType(ti->tile))->base_sprites.single_x : GetRailTypeInfo(GetRailType(ti->tile))->base_sprites.single_y;
 				DrawGroundSprite(rail, pal);
 			}

src/saveload/oldloader_sl.cpp

@@ -384,11 +384,13 @@ static bool FixTTOEngines()
 	}
 
 	/* Load the default engine set. Many of them will be overridden later */
-	uint j = 0;
-	for (uint i = 0; i < lengthof(_orig_rail_vehicle_info); i++, j++) new (GetTempDataEngine(j)) Engine(VEH_TRAIN, i);
-	for (uint i = 0; i < lengthof(_orig_road_vehicle_info); i++, j++) new (GetTempDataEngine(j)) Engine(VEH_ROAD, i);
-	for (uint i = 0; i < lengthof(_orig_ship_vehicle_info); i++, j++) new (GetTempDataEngine(j)) Engine(VEH_SHIP, i);
-	for (uint i = 0; i < lengthof(_orig_aircraft_vehicle_info); i++, j++) new (GetTempDataEngine(j)) Engine(VEH_AIRCRAFT, i);
+	{
+		uint j = 0;
+		for (uint i = 0; i < lengthof(_orig_rail_vehicle_info); i++, j++) new (GetTempDataEngine(j)) Engine(VEH_TRAIN, i);
+		for (uint i = 0; i < lengthof(_orig_road_vehicle_info); i++, j++) new (GetTempDataEngine(j)) Engine(VEH_ROAD, i);
+		for (uint i = 0; i < lengthof(_orig_ship_vehicle_info); i++, j++) new (GetTempDataEngine(j)) Engine(VEH_SHIP, i);
+		for (uint i = 0; i < lengthof(_orig_aircraft_vehicle_info); i++, j++) new (GetTempDataEngine(j)) Engine(VEH_AIRCRAFT, i);
+	}
 
 	Date aging_date = std::min(_date + DAYS_TILL_ORIGINAL_BASE_YEAR, ConvertYMDToDate(2050, 0, 1));
 

src/station_cmd.cpp

@@ -931,7 +931,7 @@ static CommandCost CheckFlatLandRailStation(TileArea tile_area, DoCommandFlag fl
 							affected_vehicles.push_back(v);
 						}
 					}
-					CommandCost ret = Command<CMD_REMOVE_SINGLE_RAIL>::Do(flags, tile_cur, track);
+					ret = Command<CMD_REMOVE_SINGLE_RAIL>::Do(flags, tile_cur, track);
 					if (ret.Failed()) return ret;
 					cost.AddCost(ret);
 					/* With flags & ~DC_EXEC CmdLandscapeClear would fail since the rail still exists */
@@ -1018,7 +1018,7 @@ static CommandCost CheckFlatLandRoadStop(TileArea tile_area, DoCommandFlag flags
 					if (road_owner == OWNER_TOWN) {
 						if (!_settings_game.construction.road_stop_on_town_road) return_cmd_error(STR_ERROR_DRIVE_THROUGH_ON_TOWN_ROAD);
 					} else if (!_settings_game.construction.road_stop_on_competitor_road && road_owner != OWNER_NONE) {
-						CommandCost ret = CheckOwnership(road_owner);
+						ret = CheckOwnership(road_owner);
 						if (ret.Failed()) return ret;
 					}
 					uint num_pieces = CountBits(GetRoadBits(cur_tile, RTT_ROAD));
@@ -1026,7 +1026,7 @@ static CommandCost CheckFlatLandRoadStop(TileArea tile_area, DoCommandFlag flags
 					if (RoadTypeIsRoad(rt) && !HasPowerOnRoad(rt, road_rt)) return_cmd_error(STR_ERROR_NO_SUITABLE_ROAD);
 
 					if (GetDisallowedRoadDirections(cur_tile) != DRD_NONE && road_owner != OWNER_TOWN) {
-						CommandCost ret = CheckOwnership(road_owner);
+						ret = CheckOwnership(road_owner);
 						if (ret.Failed()) return ret;
 					}
 
@@ -1044,7 +1044,7 @@ static CommandCost CheckFlatLandRoadStop(TileArea tile_area, DoCommandFlag flags
 							/* Disallow breaking end-of-line of someone else
 							 * so trams can still reverse on this tile. */
 							HasExactlyOneBit(GetRoadBits(cur_tile, RTT_TRAM)))) {
-						CommandCost ret = CheckOwnership(tram_owner);
+						ret = CheckOwnership(tram_owner);
 						if (ret.Failed()) return ret;
 					}
 					uint num_pieces = CountBits(GetRoadBits(cur_tile, RTT_TRAM));
@@ -1308,7 +1308,7 @@ CommandCost CmdBuildRailStation(DoCommandFlag flags, TileIndex tile_org, RailTyp
 	if (ret.Failed()) return ret;
 
 	if (st != nullptr && st->train_station.tile != INVALID_TILE) {
-		CommandCost ret = CanExpandRailStation(st, new_location, axis);
+		ret = CanExpandRailStation(st, new_location, axis);
 		if (ret.Failed()) return ret;
 	}
 
@@ -1573,7 +1573,7 @@ CommandCost RemoveFromRailBaseStation(TileArea ta, std::vector<T *> &affected_st
 		if (st == nullptr) continue;
 
 		if (_current_company != OWNER_WATER) {
-			CommandCost ret = CheckOwnership(st->owner);
+			ret = CheckOwnership(st->owner);
 			error.AddCost(ret);
 			if (ret.Failed()) continue;
 		}
@@ -2236,13 +2236,13 @@ CommandCost CmdBuildAirport(DoCommandFlag flags, TileIndex tile, byte airport_ty
 		return_cmd_error(STR_ERROR_STATION_TOO_SPREAD_OUT);
 	}
 
-	AirportTileTableIterator iter(as->table[layout], tile);
-	CommandCost cost = CheckFlatLandAirport(iter, flags);
+	AirportTileTableIterator tile_iter(as->table[layout], tile);
+	CommandCost cost = CheckFlatLandAirport(tile_iter, flags);
 	if (cost.Failed()) return cost;
 
 	/* The noise level is the noise from the airport and reduce it to account for the distance to the town center. */
 	uint dist;
-	Town *nearest = AirportGetNearestTown(as, iter, dist);
+	Town *nearest = AirportGetNearestTown(as, tile_iter, dist);
 	uint newnoise_level = GetAirportNoiseLevelForDistance(as, dist);
 
 	/* Check if local auth would allow a new airport */
@@ -2986,7 +2986,6 @@ draw_default_foundation:
 
 			/* PBS debugging, draw reserved tracks darker */
 			if (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation && HasStationRail(ti->tile) && HasStationReservation(ti->tile)) {
-				const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
 				DrawGroundSprite(GetRailStationAxis(ti->tile) == AXIS_X ? rti->base_sprites.single_x : rti->base_sprites.single_y, PALETTE_CRASH);
 			}
 		}
@@ -3033,17 +3032,17 @@ void StationPickerDrawSprite(int x, int y, StationType st, RailType railtype, Ro
 	int32 total_offset = 0;
 	PaletteID pal = COMPANY_SPRITE_COLOUR(_local_company);
 	const DrawTileSprites *t = GetStationTileLayout(st, image);
-	const RailtypeInfo *rti = nullptr;
+	const RailtypeInfo *railtype_info = nullptr;
 
 	if (railtype != INVALID_RAILTYPE) {
-		rti = GetRailTypeInfo(railtype);
-		total_offset = rti->GetRailtypeSpriteOffset();
+		railtype_info = GetRailTypeInfo(railtype);
+		total_offset = railtype_info->GetRailtypeSpriteOffset();
 	}
 
 	SpriteID img = t->ground.sprite;
 	RailTrackOffset overlay_offset;
-	if (rti != nullptr && rti->UsesOverlay() && SplitGroundSpriteForOverlay(nullptr, &img, &overlay_offset)) {
-		SpriteID ground = GetCustomRailSprite(rti, INVALID_TILE, RTSG_GROUND);
+	if (railtype_info != nullptr && railtype_info->UsesOverlay() && SplitGroundSpriteForOverlay(nullptr, &img, &overlay_offset)) {
+		SpriteID ground = GetCustomRailSprite(railtype_info, INVALID_TILE, RTSG_GROUND);
 		DrawSprite(img, PAL_NONE, x, y);
 		DrawSprite(ground + overlay_offset, PAL_NONE, x, y);
 	} else {
@@ -3051,25 +3050,25 @@ void StationPickerDrawSprite(int x, int y, StationType st, RailType railtype, Ro
 	}
 
 	if (roadtype != INVALID_ROADTYPE) {
-		const RoadTypeInfo* rti = GetRoadTypeInfo(roadtype);
+		const RoadTypeInfo *roadtype_info = GetRoadTypeInfo(roadtype);
 		if (image >= 4) {
 			/* Drive-through stop */
 			uint sprite_offset = 5 - image;
 
 			/* Road underlay takes precedence over tram */
-			if (rti->UsesOverlay()) {
-				SpriteID ground = GetCustomRoadSprite(rti, INVALID_TILE, ROTSG_GROUND);
+			if (roadtype_info->UsesOverlay()) {
+				SpriteID ground = GetCustomRoadSprite(roadtype_info, INVALID_TILE, ROTSG_GROUND);
 				DrawSprite(ground + sprite_offset, PAL_NONE, x, y);
 
-				SpriteID overlay = GetCustomRoadSprite(rti, INVALID_TILE, ROTSG_OVERLAY);
+				SpriteID overlay = GetCustomRoadSprite(roadtype_info, INVALID_TILE, ROTSG_OVERLAY);
 				if (overlay) DrawSprite(overlay + sprite_offset, PAL_NONE, x, y);
 			} else if (RoadTypeIsTram(roadtype)) {
 				DrawSprite(SPR_TRAMWAY_TRAM + sprite_offset, PAL_NONE, x, y);
 			}
 		} else {
 			/* Drive-in stop */
-			if (RoadTypeIsRoad(roadtype) && rti->UsesOverlay()) {
-				SpriteID ground = GetCustomRoadSprite(rti, INVALID_TILE, ROTSG_ROADSTOP);
+			if (RoadTypeIsRoad(roadtype) && roadtype_info->UsesOverlay()) {
+				SpriteID ground = GetCustomRoadSprite(roadtype_info, INVALID_TILE, ROTSG_ROADSTOP);
 				DrawSprite(ground + image, PAL_NONE, x, y);
 			}
 		}

src/strgen/strgen.cpp

@@ -472,9 +472,9 @@ int CDECL main(int argc, char *argv[])
 
 			case 'P':
 				printf("name\tflags\tdefault\tdescription\n");
-				for (size_t i = 0; i < lengthof(_pragmas); i++) {
+				for (size_t j = 0; j < lengthof(_pragmas); j++) {
 					printf("\"%s\"\t%s\t\"%s\"\t\"%s\"\n",
-							_pragmas[i][0], _pragmas[i][1], _pragmas[i][2], _pragmas[i][3]);
+							_pragmas[j][0], _pragmas[j][1], _pragmas[j][2], _pragmas[j][3]);
 				}
 				return 0;
 

src/strgen/strgen_base.cpp

@@ -877,7 +877,7 @@ static int TranslateArgumentIdx(int argidx, int offset)
 	}
 
 	for (int i = sum = 0; i < argidx; i++) {
-		const CmdStruct *cs = _cur_pcs.cmd[i];
+		cs = _cur_pcs.cmd[i];
 
 		sum += (cs != nullptr) ? cs->consumes : 1;
 	}

src/strings.cpp

@@ -938,7 +938,7 @@ static char *FormatString(char *buff, const char *str_arg, StringParameters *arg
 					buff = GetStringWithArgs(buff, MakeStringID(TEXT_TAB_GAMESCRIPT_START, stringid), &sub_args, last, true);
 				}
 
-				for (int i = 0; i < 20; i++) {
+				for (i = 0; i < 20; i++) {
 					if (sub_args_need_free[i]) free((void *)sub_args.GetParam(i));
 				}
 				break;
@@ -1044,19 +1044,19 @@ static char *FormatString(char *buff, const char *str_arg, StringParameters *arg
 
 			case SCC_RAW_STRING_POINTER: { // {RAW_STRING}
 				if (game_script) break;
-				const char *str = (const char *)(size_t)args->GetInt64(SCC_RAW_STRING_POINTER);
-				buff = FormatString(buff, str, args, last);
+				const char *raw_string = (const char *)(size_t)args->GetInt64(SCC_RAW_STRING_POINTER);
+				buff = FormatString(buff, raw_string, args, last);
 				break;
 			}
 
 			case SCC_STRING: {// {STRING}
-				StringID str = args->GetInt32(SCC_STRING);
-				if (game_script && GetStringTab(str) != TEXT_TAB_GAMESCRIPT_START) break;
+				StringID string_id = args->GetInt32(SCC_STRING);
+				if (game_script && GetStringTab(string_id) != TEXT_TAB_GAMESCRIPT_START) break;
 				/* WARNING. It's prohibited for the included string to consume any arguments.
 				 * For included strings that consume argument, you should use STRING1, STRING2 etc.
 				 * To debug stuff you can set argv to nullptr and it will tell you */
 				StringParameters tmp_params(args->GetDataPointer(), args->GetDataLeft(), nullptr);
-				buff = GetStringWithArgs(buff, str, &tmp_params, last, next_substr_case_index, game_script);
+				buff = GetStringWithArgs(buff, string_id, &tmp_params, last, next_substr_case_index, game_script);
 				next_substr_case_index = 0;
 				break;
 			}
@@ -1069,14 +1069,14 @@ static char *FormatString(char *buff, const char *str_arg, StringParameters *arg
 			case SCC_STRING6:
 			case SCC_STRING7: { // {STRING1..7}
 				/* Strings that consume arguments */
-				StringID str = args->GetInt32(b);
-				if (game_script && GetStringTab(str) != TEXT_TAB_GAMESCRIPT_START) break;
+				StringID string_id = args->GetInt32(b);
+				if (game_script && GetStringTab(string_id) != TEXT_TAB_GAMESCRIPT_START) break;
 				uint size = b - SCC_STRING1 + 1;
 				if (game_script && size > args->GetDataLeft()) {
 					buff = strecat(buff, "(too many parameters)", last);
 				} else {
 					StringParameters sub_args(*args, size);
-					buff = GetStringWithArgs(buff, str, &sub_args, last, next_substr_case_index, game_script);
+					buff = GetStringWithArgs(buff, string_id, &sub_args, last, next_substr_case_index, game_script);
 				}
 				next_substr_case_index = 0;
 				break;
@@ -1456,7 +1456,7 @@ static char *FormatString(char *buff, const char *str_arg, StringParameters *arg
 					StringParameters tmp_params(args_array);
 					buff = GetStringWithArgs(buff, STR_JUST_RAW_STRING, &tmp_params, last);
 				} else {
-					StringID str = st->string_id;
+					StringID string_id = st->string_id;
 					if (st->indtype != IT_INVALID) {
 						/* Special case where the industry provides the name for the station */
 						const IndustrySpec *indsp = GetIndustrySpec(st->indtype);
@@ -1465,14 +1465,14 @@ static char *FormatString(char *buff, const char *str_arg, StringParameters *arg
 						 * thus cause very strange things. Here we check for that before we
 						 * actually set the station name. */
 						if (indsp->station_name != STR_NULL && indsp->station_name != STR_UNDEFINED) {
-							str = indsp->station_name;
+							string_id = indsp->station_name;
 						}
 					}
 
 					uint64 args_array[] = {STR_TOWN_NAME, st->town->index, st->index};
 					WChar types_array[] = {0, SCC_TOWN_NAME, SCC_NUM};
 					StringParameters tmp_params(args_array, 3, types_array);
-					buff = GetStringWithArgs(buff, str, &tmp_params, last);
+					buff = GetStringWithArgs(buff, string_id, &tmp_params, last);
 				}
 				break;
 			}
@@ -1502,9 +1502,9 @@ static char *FormatString(char *buff, const char *str_arg, StringParameters *arg
 				} else {
 					int64 args_array[] = {wp->town->index, wp->town_cn + 1};
 					StringParameters tmp_params(args_array);
-					StringID str = ((wp->string_id == STR_SV_STNAME_BUOY) ? STR_FORMAT_BUOY_NAME : STR_FORMAT_WAYPOINT_NAME);
-					if (wp->town_cn != 0) str++;
-					buff = GetStringWithArgs(buff, str, &tmp_params, last);
+					StringID string_id = ((wp->string_id == STR_SV_STNAME_BUOY) ? STR_FORMAT_BUOY_NAME : STR_FORMAT_WAYPOINT_NAME);
+					if (wp->town_cn != 0) string_id++;
+					buff = GetStringWithArgs(buff, string_id, &tmp_params, last);
 				}
 				break;
 			}
@@ -1526,16 +1526,16 @@ static char *FormatString(char *buff, const char *str_arg, StringParameters *arg
 					int64 args_array[] = {v->unitnumber};
 					StringParameters tmp_params(args_array);
 
-					StringID str;
+					StringID string_id;
 					switch (v->type) {
-						default:           str = STR_INVALID_VEHICLE; break;
-						case VEH_TRAIN:    str = STR_SV_TRAIN_NAME; break;
-						case VEH_ROAD:     str = STR_SV_ROAD_VEHICLE_NAME; break;
-						case VEH_SHIP:     str = STR_SV_SHIP_NAME; break;
-						case VEH_AIRCRAFT: str = STR_SV_AIRCRAFT_NAME; break;
+						default:           string_id = STR_INVALID_VEHICLE; break;
+						case VEH_TRAIN:    string_id = STR_SV_TRAIN_NAME; break;
+						case VEH_ROAD:     string_id = STR_SV_ROAD_VEHICLE_NAME; break;
+						case VEH_SHIP:     string_id = STR_SV_SHIP_NAME; break;
+						case VEH_AIRCRAFT: string_id = STR_SV_AIRCRAFT_NAME; break;
 					}
 
-					buff = GetStringWithArgs(buff, str, &tmp_params, last);
+					buff = GetStringWithArgs(buff, string_id, &tmp_params, last);
 				}
 				break;
 			}

src/timetable_gui.cpp

@@ -91,15 +91,15 @@ static void FillTimetableArrivalDepartureTable(const Vehicle *v, VehicleOrderID
 	assert(v->GetNumOrders() >= 2);
 	assert(start < v->GetNumOrders());
 
-	Ticks sum = offset;
-	VehicleOrderID i = start;
-	const Order *order = v->GetOrder(i);
-
 	/* Pre-initialize with unknown time */
 	for (int i = 0; i < v->GetNumOrders(); ++i) {
 		table[i].arrival = table[i].departure = INVALID_TICKS;
 	}
 
+	Ticks sum = offset;
+	VehicleOrderID i = start;
+	const Order *order = v->GetOrder(i);
+
 	/* Cyclically loop over all orders until we reach the current one again.
 	 * As we may start at the current order, do a post-checking loop */
 	do {

src/town_cmd.cpp

@@ -93,7 +93,7 @@ static bool TestTownOwnsBridge(TileIndex tile, const Town *t)
 
 	if (!town_owned) {
 		/* Or other adjacent road */
-		TileIndex adjacent = tile + TileOffsByDiagDir(ReverseDiagDir(GetTunnelBridgeDirection(GetOtherTunnelBridgeEnd(tile))));
+		adjacent = tile + TileOffsByDiagDir(ReverseDiagDir(GetTunnelBridgeDirection(GetOtherTunnelBridgeEnd(tile))));
 		town_owned = IsTileType(adjacent, MP_ROAD) && IsTileOwner(adjacent, OWNER_TOWN) && GetTownIndex(adjacent) == t->index;
 	}
 
@@ -2656,15 +2656,15 @@ static bool BuildTownHouse(Town *t, TileIndex tile)
 		byte construction_stage = 0;
 
 		if (_generating_world || _game_mode == GM_EDITOR) {
-			uint32 r = Random();
+			uint32 construction_random = Random();
 
 			construction_stage = TOWN_HOUSE_COMPLETED;
-			if (Chance16(1, 7)) construction_stage = GB(r, 0, 2);
+			if (Chance16(1, 7)) construction_stage = GB(construction_random, 0, 2);
 
 			if (construction_stage == TOWN_HOUSE_COMPLETED) {
 				ChangePopulation(t, hs->population);
 			} else {
-				construction_counter = GB(r, 2, 2);
+				construction_counter = GB(construction_random, 2, 2);
 			}
 		}
 

src/train_cmd.cpp

@@ -1202,7 +1202,7 @@ CommandCost CmdMoveRailVehicle(DoCommandFlag flags, VehicleID src_veh, VehicleID
 		dst = Train::GetIfValid(dest_veh);
 		if (dst == nullptr) return CMD_ERROR;
 
-		CommandCost ret = CheckOwnership(dst->owner);
+		ret = CheckOwnership(dst->owner);
 		if (ret.Failed()) return ret;
 
 		/* Do not allow appending to crashed vehicles, too */
@@ -1271,7 +1271,7 @@ CommandCost CmdMoveRailVehicle(DoCommandFlag flags, VehicleID src_veh, VehicleID
 		/* If the autoreplace flag is set we do not need to test for the validity
 		 * because we are going to revert the train to its original state. As we
 		 * assume the original state was correct autoreplace can skip this. */
-		CommandCost ret = ValidateTrains(original_dst_head, dst_head, original_src_head, src_head, true);
+		ret = ValidateTrains(original_dst_head, dst_head, original_src_head, src_head, true);
 		if (ret.Failed()) {
 			/* Restore the train we had. */
 			RestoreTrainBackup(original_src);

src/tunnelbridge_cmd.cpp

@@ -862,7 +862,7 @@ static CommandCost DoClearTunnel(TileIndex tile, DoCommandFlag flags)
 
 		/* Check if you are allowed to remove the tunnel owned by a town
 		 * Removal depends on difficulty settings */
-		CommandCost ret = CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE);
+		ret = CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE);
 		if (ret.Failed()) return ret;
 	}
 
@@ -943,7 +943,7 @@ static CommandCost DoClearBridge(TileIndex tile, DoCommandFlag flags)
 
 		/* Check if you are allowed to remove the bridge owned by a town
 		 * Removal depends on difficulty settings */
-		CommandCost ret = CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE);
+		ret = CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE);
 		if (ret.Failed()) return ret;
 	}
 

src/vehicle_gui.cpp

@@ -3226,8 +3226,8 @@ public:
 		}
 		/* The same system applies to widget WID_VV_REFIT_VEH and VVW_WIDGET_TURN_AROUND.*/
 		if (v->IsGroundVehicle()) {
-			PlaneSelections plane = veh_stopped ? SEL_RT_REFIT : SEL_RT_TURN_AROUND;
-			NWidgetStacked *nwi = this->GetWidget<NWidgetStacked>(WID_VV_SELECT_REFIT_TURN);
+			plane = veh_stopped ? SEL_RT_REFIT : SEL_RT_TURN_AROUND;
+			nwi = this->GetWidget<NWidgetStacked>(WID_VV_SELECT_REFIT_TURN);
 			if (nwi->shown_plane + SEL_RT_BASEPLANE != plane) {
 				this->SelectPlane(plane);
 				this->SetWidgetDirty(WID_VV_SELECT_REFIT_TURN);

src/video/opengl.cpp

@@ -1120,8 +1120,8 @@ void OpenGLBackend::PopulateCursorCache()
 		if (!this->cursor_cache.Contains(sprite)) {
 			Sprite *old = this->cursor_cache.Insert(sprite, (Sprite *)GetRawSprite(sprite, ST_NORMAL, &SimpleSpriteAlloc, this));
 			if (old != nullptr) {
-				OpenGLSprite *sprite = (OpenGLSprite *)old->data;
-				sprite->~OpenGLSprite();
+				OpenGLSprite *gl_sprite = (OpenGLSprite *)old->data;
+				gl_sprite->~OpenGLSprite();
 				free(old);
 			}
 		}

src/viewport.cpp

@@ -1356,9 +1356,6 @@ static void ViewportAddKdtreeSigns(DrawPixelInfo *dpi)
 	bool show_signs = HasBit(_display_opt, DO_SHOW_SIGNS) && !IsInvisibilitySet(TO_SIGNS);
 	bool show_competitors = HasBit(_display_opt, DO_SHOW_COMPETITOR_SIGNS);
 
-	const BaseStation *st;
-	const Sign *si;
-
 	/* Collect all the items first and draw afterwards, to ensure layering */
 	std::vector<const BaseStation *> stations;
 	std::vector<const Town *> towns;
@@ -1366,34 +1363,36 @@ static void ViewportAddKdtreeSigns(DrawPixelInfo *dpi)
 
 	_viewport_sign_kdtree.FindContained(search_rect.left, search_rect.top, search_rect.right, search_rect.bottom, [&](const ViewportSignKdtreeItem & item) {
 		switch (item.type) {
-			case ViewportSignKdtreeItem::VKI_STATION:
+			case ViewportSignKdtreeItem::VKI_STATION: {
 				if (!show_stations) break;
-				st = BaseStation::Get(item.id.station);
+				const BaseStation *st = BaseStation::Get(item.id.station);
 
 				/* Don't draw if station is owned by another company and competitor station names are hidden. Stations owned by none are never ignored. */
 				if (!show_competitors && _local_company != st->owner && st->owner != OWNER_NONE) break;
 
 				stations.push_back(st);
 				break;
+			}
 
-			case ViewportSignKdtreeItem::VKI_WAYPOINT:
+			case ViewportSignKdtreeItem::VKI_WAYPOINT: {
 				if (!show_waypoints) break;
-				st = BaseStation::Get(item.id.station);
+				const BaseStation *st = BaseStation::Get(item.id.station);
 
 				/* Don't draw if station is owned by another company and competitor station names are hidden. Stations owned by none are never ignored. */
 				if (!show_competitors && _local_company != st->owner && st->owner != OWNER_NONE) break;
 
 				stations.push_back(st);
 				break;
+			}
 
 			case ViewportSignKdtreeItem::VKI_TOWN:
 				if (!show_towns) break;
 				towns.push_back(Town::Get(item.id.town));
 				break;
 
-			case ViewportSignKdtreeItem::VKI_SIGN:
+			case ViewportSignKdtreeItem::VKI_SIGN: {
 				if (!show_signs) break;
-				si = Sign::Get(item.id.sign);
+				const Sign *si = Sign::Get(item.id.sign);
 
 				/* Don't draw if sign is owned by another company and competitor signs should be hidden.
 				* Note: It is intentional that also signs owned by OWNER_NONE are hidden. Bankrupt
@@ -1402,6 +1401,7 @@ static void ViewportAddKdtreeSigns(DrawPixelInfo *dpi)
 
 				signs.push_back(si);
 				break;
+			}
 
 			default:
 				NOT_REACHED();

src/water_cmd.cpp

@@ -264,7 +264,7 @@ static CommandCost RemoveShipDepot(TileIndex tile, DoCommandFlag flags)
 
 	/* do not check for ship on tile when company goes bankrupt */
 	if (!(flags & DC_BANKRUPT)) {
-		CommandCost ret = EnsureNoVehicleOnGround(tile);
+		ret = EnsureNoVehicleOnGround(tile);
 		if (ret.Succeeded()) ret = EnsureNoVehicleOnGround(tile2);
 		if (ret.Failed()) return ret;
 	}
@@ -539,7 +539,7 @@ static CommandCost ClearTile_Water(TileIndex tile, DoCommandFlag flags)
 
 			Owner owner = GetTileOwner(tile);
 			if (owner != OWNER_WATER && owner != OWNER_NONE) {
-				CommandCost ret = CheckTileOwnership(tile);
+				ret = CheckTileOwnership(tile);
 				if (ret.Failed()) return ret;
 			}
 

src/waypoint_cmd.cpp

@@ -217,11 +217,11 @@ CommandCost CmdBuildRailWaypoint(DoCommandFlag flags, TileIndex start_tile, Axis
 
 		/* check if we want to expand an already existing waypoint? */
 		if (wp->train_station.tile != INVALID_TILE) {
-			CommandCost ret = CanExpandRailStation(wp, new_location, axis);
+			ret = CanExpandRailStation(wp, new_location, axis);
 			if (ret.Failed()) return ret;
 		}
 
-		CommandCost ret = wp->rect.BeforeAddRect(start_tile, width, height, StationRect::ADD_TEST);
+		ret = wp->rect.BeforeAddRect(start_tile, width, height, StationRect::ADD_TEST);
 		if (ret.Failed()) return ret;
 	} else {
 		/* allocate and initialize new waypoint */

src/widget.cpp

@@ -3209,7 +3209,7 @@ static int MakeWidgetTree(const NWidgetPart *parts, int count, NWidgetBase **par
 		if (fill_sub && (tp == NWID_HORIZONTAL || tp == NWID_HORIZONTAL_LTR || tp == NWID_VERTICAL || tp == NWID_MATRIX
 							|| tp == WWT_PANEL || tp == WWT_FRAME || tp == WWT_INSET || tp == NWID_SELECTION)) {
 			NWidgetBase *sub_ptr = sub_widget;
-			int num_used = MakeWidgetTree(parts, count - total_used, &sub_ptr, biggest_index);
+			num_used = MakeWidgetTree(parts, count - total_used, &sub_ptr, biggest_index);
 			parts += num_used;
 			total_used += num_used;
 		}

src/window.cpp

@@ -257,7 +257,7 @@ void Window::SetWidgetHighlight(byte widget_index, TextColour highlighted_colour
 		/* If we disable a highlight, check all widgets if anyone still has a highlight */
 		bool valid = false;
 		for (uint i = 0; i < this->nested_array_size; i++) {
-			NWidgetBase *nwid = this->GetWidget<NWidgetBase>(i);
+			nwid = this->GetWidget<NWidgetBase>(i);
 			if (nwid == nullptr) continue;
 			if (!nwid->IsHighlighted()) continue;