(svn r19400) -Codechange: CheckforTownRating returns a CommandCost.

4 files changed, 21 insertions, 15 deletions

diff --git a/src/road_cmd.cpp b/src/road_cmd.cpp
index 366f6bd0c..5d83abeef 100644
--- a/src/road_cmd.cpp
+++ b/src/road_cmd.cpp
@@ -140,7 +140,9 @@ bool CheckAllowRemoveRoad(TileIndex tile, RoadBits remove, Owner owner, RoadType
 
 	/* check if you're allowed to remove the street owned by a town
 	 * removal allowance depends on difficulty setting */
-	if (!CheckforTownRating(flags, t, ROAD_REMOVE)) return false;
+	CommandCost ret = CheckforTownRating(flags, t, ROAD_REMOVE);
+	ret.SetGlobalErrorMessage();
+	if (ret.Failed()) return false;
 
 	/* Get a bitmask of which neighbouring roads has a tile */
 	RoadBits n = ROAD_NONE;
diff --git a/src/town.h b/src/town.h
index f1571d241..25794f084 100644
--- a/src/town.h
+++ b/src/town.h
@@ -179,7 +179,7 @@ enum {
 	TOWN_HAS_STADIUM    = 2    ///< There can be only one stadium by town.
 };
 
-bool CheckforTownRating(DoCommandFlag flags, Town *t, TownRatingCheckType type);
+CommandCost CheckforTownRating(DoCommandFlag flags, Town *t, TownRatingCheckType type);
 
 
 TileIndexDiff GetHouseNorthPart(HouseID &house);
diff --git a/src/town_cmd.cpp b/src/town_cmd.cpp
index 67d6c7546..2a4e3674d 100644
--- a/src/town_cmd.cpp
+++ b/src/town_cmd.cpp
@@ -2795,12 +2795,19 @@ void ChangeTownRating(Town *t, int add, int max, DoCommandFlag flags)
 	}
 }
 
-bool CheckforTownRating(DoCommandFlag flags, Town *t, TownRatingCheckType type)
+/**
+ * Does the town authority allow the (destructive) action of the current company?
+ * @param flags Checking flags of the command.
+ * @param t     Town that must allow the company action.
+ * @param type  Type of action that is wanted.
+ * @return A succeeded command if the action is allowed, a failed command if it is not allowed.
+ */
+CommandCost CheckforTownRating(DoCommandFlag flags, Town *t, TownRatingCheckType type)
 {
 	/* if magic_bulldozer cheat is active, town doesn't restrict your destructive actions */
 	if (t == NULL || !Company::IsValidID(_current_company) ||
 			_cheats.magic_bulldozer.value || (flags & DC_NO_TEST_TOWN_RATING)) {
-		return true;
+		return CommandCost();
 	}
 
 	/* minimum rating needed to be allowed to remove stuff */
@@ -2819,11 +2826,10 @@ bool CheckforTownRating(DoCommandFlag flags, Town *t, TownRatingCheckType type)
 
 	if (GetRating(t) < needed) {
 		SetDParam(0, t->index);
-		_error_message = STR_ERROR_LOCAL_AUTHORITY_REFUSES_TO_ALLOW_THIS;
-		return false;
+		return_cmd_error(STR_ERROR_LOCAL_AUTHORITY_REFUSES_TO_ALLOW_THIS);
 	}
 
-	return true;
+	return CommandCost();
 }
 
 void TownsMonthlyLoop()
diff --git a/src/tunnelbridge_cmd.cpp b/src/tunnelbridge_cmd.cpp
index aefb074d3..a5d724108 100644
--- a/src/tunnelbridge_cmd.cpp
+++ b/src/tunnelbridge_cmd.cpp
@@ -638,10 +638,9 @@ 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 */
-		if (!CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE)) {
-			SetDParam(0, t->index);
-			return_cmd_error(STR_ERROR_LOCAL_AUTHORITY_REFUSES_TO_ALLOW_THIS);
-		}
+		CommandCost ret = CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE);
+		ret.SetGlobalErrorMessage();
+		if (ret.Failed()) return ret;
 	}
 
 	/* checks if the owner is town then decrease town rating by RATING_TUNNEL_BRIDGE_DOWN_STEP until
@@ -706,10 +705,9 @@ 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 */
-		if (!CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE)) {
-			SetDParam(0, t->index);
-			return_cmd_error(STR_ERROR_LOCAL_AUTHORITY_REFUSES_TO_ALLOW_THIS);
-		}
+		CommandCost ret = CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE);
+		ret.SetGlobalErrorMessage();
+		if (ret.Failed()) return ret;
 	}
 
 	/* checks if the owner is town then decrease town rating by RATING_TUNNEL_BRIDGE_DOWN_STEP until