Fix #12014: Remove water when area clearing ship depot (#12030)

src/landscape.cpp

@@ -712,6 +712,8 @@ std::tuple<CommandCost, Money> CmdClearArea(DoCommandFlag flags, TileIndex tile,
 	const Company *c = (flags & (DC_AUTO | DC_BANKRUPT)) ? nullptr : Company::GetIfValid(_current_company);
 	int limit = (c == nullptr ? INT32_MAX : GB(c->clear_limit, 16, 16));
 
+	if (tile != start_tile) flags |= DC_FORCE_CLEAR_TILE;
+
 	std::unique_ptr<TileIterator> iter = TileIterator::Create(tile, start_tile, diagonal);
 	for (; *iter != INVALID_TILE; ++(*iter)) {
 		TileIndex t = *iter;

src/water_cmd.cpp

@@ -273,16 +273,19 @@ static CommandCost RemoveShipDepot(TileIndex tile, DoCommandFlag flags)
 		if (ret.Failed()) return ret;
 	}
 
+	bool do_clear = (flags & DC_FORCE_CLEAR_TILE) != 0;
+
 	if (flags & DC_EXEC) {
 		delete Depot::GetByTile(tile);
 
 		Company *c = Company::GetIfValid(GetTileOwner(tile));
 		if (c != nullptr) {
 			c->infrastructure.water -= 2 * LOCK_DEPOT_TILE_FACTOR;
+			if (do_clear && GetWaterClass(tile) == WATER_CLASS_CANAL) c->infrastructure.water--;
 			DirtyCompanyInfrastructureWindows(c->index);
 		}
 
-		MakeWaterKeepingClass(tile,  GetTileOwner(tile));
+		if (!do_clear) MakeWaterKeepingClass(tile,  GetTileOwner(tile));
 		MakeWaterKeepingClass(tile2, GetTileOwner(tile2));
 	}