--- a/road_cmd.c	Wed Jan 31 22:08:23 2007 +0000
+++ b/road_cmd.c	Thu Feb 08 10:00:22 2007 +0000
@@ -293,7 +293,7 @@
 
 	/* Road pieces are max 4 bitset values (NE, NW, SE, SW) and town can only be non-zero
 	 * if a non-player is building the road */
-	if ((p1 >> 4) || (IsValidPlayer(_current_player) && p2 != 0) || !IsValidTownID(p2)) return CMD_ERROR;
+	if ((p1 >> 4) || (IsValidPlayer(_current_player) && p2 != 0) || (_current_player == OWNER_TOWN && !IsValidTownID(p2))) return CMD_ERROR;
 	pieces = p1;
 
 	tileh = GetTileSlope(tile, NULL);

--- a/station_cmd.c	Wed Jan 31 22:08:23 2007 +0000
+++ b/station_cmd.c	Thu Feb 08 10:00:22 2007 +0000
@@ -1895,13 +1895,22 @@
 	if (!EnsureNoVehicle(tile)) return CMD_ERROR;
 
 	if (flags & DC_EXEC) {
+		Owner o;
 		st->dock_tile = 0;
 		/* Buoys are marked in the Station struct by this flag. Yes, it is this
 		 * braindead.. */
 		st->facilities &= ~FACIL_DOCK;
 		st->had_vehicle_of_type &= ~HVOT_BUOY;
 
-		MakeWater(tile);
+		/* We have to set the water tile's state to the same state as before the
+		 * buoy was placed. Otherwise one could plant a buoy on a canal edge,
+		 * remove it and flood the land (if the canal edge is at level 0) */
+		o = GetTileOwner(tile);
+		if (o == OWNER_WATER) {
+			MakeWater(tile);
+		} else {
+			MakeCanal(tile, o);
+		}
 		MarkTileDirtyByTile(tile);
 
 		UpdateStationVirtCoordDirty(st);

--- a/station_map.h	Wed Jan 31 22:08:23 2007 +0000
+++ b/station_map.h	Thu Feb 08 10:00:22 2007 +0000
@@ -287,7 +287,10 @@
 
 static inline void MakeBuoy(TileIndex t, StationID sid)
 {
-	MakeStation(t, OWNER_NONE, sid, GFX_BUOY_BASE);
+	/* Make the owner of the buoy tile the same as the current owner of the
+	 * water tile. In this way, we can reset the owner of the water to its
+	 * original state when the buoy gets removed. */
+	MakeStation(t, GetTileOwner(t), sid, GFX_BUOY_BASE);
 }
 
 static inline void MakeDock(TileIndex t, Owner o, StationID sid, DiagDirection d)

--- a/tunnelbridge_cmd.c	Wed Jan 31 22:08:23 2007 +0000
+++ b/tunnelbridge_cmd.c	Thu Feb 08 10:00:22 2007 +0000
@@ -541,7 +541,7 @@
 		GetTileZ(tile) != z
 	);
 
-	v = FindVehicleBetween(starttile, tile, z);
+	v = FindVehicleBetween(starttile, tile, z, false);
 	if (v != NULL) {
 		_error_message = v->type == VEH_Train ?
 			STR_5000_TRAIN_IN_TUNNEL : STR_5001_ROAD_VEHICLE_IN_TUNNEL;
@@ -688,7 +688,7 @@
 	v = FindVehicleBetween(
 		tile    + delta,
 		endtile - delta,
-		GetBridgeHeightRamp(tile)
+		GetBridgeHeightRamp(tile), false
 	);
 	if (v != NULL) return_cmd_error(VehicleInTheWayErrMsg(v));
 
@@ -820,7 +820,7 @@
 
 		if (!EnsureNoVehicle(tile) ||
 				!EnsureNoVehicle(endtile) ||
-				FindVehicleBetween(tile, endtile, GetBridgeHeightRamp(tile)) != NULL) {
+				FindVehicleBetween(tile, endtile, GetBridgeHeightRamp(tile), false) != NULL) {
 			return_cmd_error(STR_8803_TRAIN_IN_THE_WAY);
 		}
 

--- a/vehicle.c	Wed Jan 31 22:08:23 2007 +0000
+++ b/vehicle.c	Thu Feb 08 10:00:22 2007 +0000
@@ -174,7 +174,7 @@
 	return VehicleFromPos(tile, &ti, EnsureNoVehicleProcZ);
 }
 
-Vehicle *FindVehicleBetween(TileIndex from, TileIndex to, byte z)
+Vehicle *FindVehicleBetween(TileIndex from, TileIndex to, byte z, bool without_crashed)
 {
 	int x1 = TileX(from);
 	int y1 = TileY(from);
@@ -188,6 +188,7 @@
 		intswap(y1,y2);
 	}
 	FOR_ALL_VEHICLES(veh) {
+		if (without_crashed && (veh->vehstatus & VS_CRASHED) != 0) continue;
 		if ((veh->type == VEH_Train || veh->type == VEH_Road) && (z==0xFF || veh->z_pos == z)) {
 			if ((veh->x_pos>>4) >= x1 && (veh->x_pos>>4) <= x2 &&
 					(veh->y_pos>>4) >= y1 && (veh->y_pos>>4) <= y2) {

--- a/vehicle.h	Wed Jan 31 22:08:23 2007 +0000
+++ b/vehicle.h	Thu Feb 08 10:00:22 2007 +0000
@@ -299,7 +299,7 @@
 uint32 VehicleEnterTile(Vehicle *v, TileIndex tile, int x, int y);
 
 StringID VehicleInTheWayErrMsg(const Vehicle* v);
-Vehicle *FindVehicleBetween(TileIndex from, TileIndex to, byte z);
+Vehicle *FindVehicleBetween(TileIndex from, TileIndex to, byte z, bool without_crashed);
 TileIndex GetVehicleOutOfTunnelTile(const Vehicle *v);
 
 bool UpdateSignalsOnSegment(TileIndex tile, DiagDirection direction);

--- a/water_cmd.c	Wed Jan 31 22:08:23 2007 +0000
+++ b/water_cmd.c	Thu Feb 08 10:00:22 2007 +0000
@@ -40,6 +40,7 @@
 };
 
 
+static Vehicle *FindFloodableVehicleOnTile(TileIndex tile);
 static void FloodVehicle(Vehicle *v);
 
 /** Build a ship depot.
@@ -593,7 +594,7 @@
 
 		_current_player = OWNER_WATER;
 		{
-			Vehicle *v = FindVehicleOnTileZ(target, 0);
+			Vehicle *v = FindFloodableVehicleOnTile(target);
 			if (v != NULL) FloodVehicle(v);
 		}
 
@@ -604,6 +605,36 @@
 	}
 }
 
+/**
+ * Finds a vehicle to flood.
+ * It does not find vehicles that are already crashed on bridges, i.e. flooded.
+ * @param tile the tile where to find a vehicle to flood
+ * @return a vehicle too flood or NULL when there is no vehicle too flood.
+ */
+static Vehicle *FindFloodableVehicleOnTile(TileIndex tile)
+{
+	TileIndex end;
+	byte z;
+	Vehicle *v;
+
+	if (!IsBridgeTile(tile)) return FindVehicleOnTileZ(tile, 0);
+
+	end = GetOtherBridgeEnd(tile);
+	z = GetBridgeHeight(tile);
+
+	/* check the start tile first since as this is closest to the water */
+	v = FindVehicleOnTileZ(tile, z);
+	if (v != NULL && (v->vehstatus & VS_CRASHED) == 0) return v;
+
+	/* check a vehicle in between both bridge heads */
+	v = FindVehicleBetween(tile, end, z, true);
+	if (v != NULL) return v;
+
+	/* check the end tile last to give fleeing vehicles a chance to escape */
+	v = FindVehicleOnTileZ(end, z);
+	return (v != NULL && (v->vehstatus & VS_CRASHED) == 0) ? v : NULL;
+}
+
 static void FloodVehicle(Vehicle *v)
 {
 	if (!(v->vehstatus & VS_CRASHED)) {
@@ -628,6 +659,7 @@
 			BEGIN_ENUM_WAGONS(v)
 				if (v->cargo_type == CT_PASSENGERS) pass += v->cargo_count;
 				v->vehstatus |= VS_CRASHED;
+				MarkAllViewportsDirty(v->left_coord, v->top_coord, v->right_coord + 1, v->bottom_coord + 1);
 			END_ENUM_WAGONS(v)
 
 			v = u;
@@ -661,9 +693,8 @@
 		{{ 0, -1}, {0, 0}, {1, 0}, { 0, -1}, { 1, -1}}
 	};
 
-	/* Ensure sea-level canals do not flood */
-	if ((IsTileType(tile, MP_WATER) || IsTileType(tile, MP_TUNNELBRIDGE)) &&
-			!IsTileOwner(tile, OWNER_WATER)) return;
+	/* Ensure sea-level canals and buoys on canal borders do not flood */
+	if ((IsTileType(tile, MP_WATER) || IsTileType(tile, MP_TUNNELBRIDGE) || IsBuoyTile(tile)) && !IsTileOwner(tile, OWNER_WATER)) return;
 
 	if (IS_INT_INSIDE(TileX(tile), 1, MapSizeX() - 3 + 1) &&
 			IS_INT_INSIDE(TileY(tile), 1, MapSizeY() - 3 + 1)) {