Add setting to allow placing all NewGRF objects under bridges

src/lang/english.txt

@@ -1881,6 +1881,9 @@ STR_CONFIG_SETTING_ENABLE_ROAD_CUSTOM_BRIDGE_HEADS_HELPTEXT     :Allow road brid
 STR_CONFIG_SETTING_ENABLE_RAIL_CUSTOM_BRIDGE_HEADS              :Enable rail custom bridge heads: {STRING2}
 STR_CONFIG_SETTING_ENABLE_RAIL_CUSTOM_BRIDGE_HEADS_HELPTEXT     :Allow rail bridges to have custom, non-straight flat entry/exit tiles
 
+STR_CONFIG_SETTING_ALLOW_GRF_OBJECTS_UNDER_BRIDGES              :Allow all NewGRF objects under bridges: {STRING2}
+STR_CONFIG_SETTING_ALLOW_GRF_OBJECTS_UNDER_BRIDGES_HELPTEXT     :Allow all NewGRF objects to be built under bridges, even where not otherwise enabled by the GRF.{}This may result in graphical issues.
+
 STR_CONFIG_SETTING_QUERY_CAPTION                                :{WHITE}Change setting value
 
 STR_CONFIG_SETTING_ADJACENT_CROSSINGS                           :Close adjacent level crossings: {STRING2}

src/object_cmd.cpp

@@ -294,11 +294,13 @@ CommandCost CmdBuildObject(TileIndex tile, DoCommandFlag flags, uint32 p1, uint3
 	if (cost.Failed()) return cost;
 
 	/* Finally do a check for bridges. */
-	TILE_AREA_LOOP(t, ta) {
+	if (type < NEW_OBJECT_OFFSET || !_settings_game.construction.allow_grf_objects_under_bridges) {
-		if (IsBridgeAbove(t) && (
+		TILE_AREA_LOOP(t, ta) {
-				!(spec->flags & OBJECT_FLAG_ALLOW_UNDER_BRIDGE) ||
+			if (IsBridgeAbove(t) && (
-				(GetTileMaxZ(t) + spec->height >= GetBridgeHeight(GetSouthernBridgeEnd(t))))) {
+					!(spec->flags & OBJECT_FLAG_ALLOW_UNDER_BRIDGE) ||
-			return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
+					(GetTileMaxZ(t) + spec->height >= GetBridgeHeight(GetSouthernBridgeEnd(t))))) {
+				return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
+			}
 		}
 	}
 

src/settings_gui.cpp

@@ -1743,6 +1743,7 @@ static SettingsContainer &GetSettingsTree()
 			limitations->Add(new SettingEntry("construction.enable_remove_water"));
 			limitations->Add(new SettingEntry("construction.road_custom_bridge_heads"));
 			limitations->Add(new SettingEntry("construction.rail_custom_bridge_heads"));
+			limitations->Add(new SettingEntry("construction.allow_grf_objects_under_bridges"));
 		}
 
 		SettingsPage *disasters = main->Add(new SettingsPage(STR_CONFIG_SETTING_ACCIDENTS));

src/settings_type.h

@@ -376,6 +376,7 @@ struct ConstructionSettings {
 	uint8  road_custom_bridge_heads;         ///< allow construction of road custom bridge heads
 	bool   chunnel;                          ///< allow construction of tunnels under water
 	uint8  rail_custom_bridge_heads;         ///< allow construction of rail custom bridge heads
+	bool   allow_grf_objects_under_bridges;  ///< allow all NewGRF objects under bridges
 
 	uint32 terraform_per_64k_frames;         ///< how many tile heights may, over a long period, be terraformed per 65536 frames?
 	uint16 terraform_frame_burst;            ///< how many tile heights may, over a short period, be terraformed?

src/table/settings.ini

@@ -1473,6 +1473,15 @@ str      = STR_CONFIG_SETTING_ENABLE_RAIL_CUSTOM_BRIDGE_HEADS
 strhelp  = STR_CONFIG_SETTING_ENABLE_RAIL_CUSTOM_BRIDGE_HEADS_HELPTEXT
 patxname = ""custom_bridge_heads.construction.rail_custom_bridge_heads""
 
+[SDT_BOOL]
+base     = GameSettings
+var      = construction.allow_grf_objects_under_bridges
+def      = false
+cat      = SC_EXPERT
+str      = STR_CONFIG_SETTING_ALLOW_GRF_OBJECTS_UNDER_BRIDGES
+strhelp  = STR_CONFIG_SETTING_ALLOW_GRF_OBJECTS_UNDER_BRIDGES_HELPTEXT
+patxname = ""allow_grf_objects_under_bridges.construction.allow_grf_objects_under_bridges""
+
 [SDT_BOOL]
 base     = GameSettings
 var      = station.adjacent_stations

src/tunnelbridge_cmd.cpp

@@ -493,6 +493,7 @@ CommandCost CmdBuildBridge(TileIndex end_tile, DoCommandFlag flags, uint32 p1, u
 					break;
 
 				case MP_OBJECT: {
+					if (_settings_game.construction.allow_grf_objects_under_bridges && GetObjectType(tile) >= NEW_OBJECT_OFFSET) break;
 					const ObjectSpec *spec = ObjectSpec::GetByTile(tile);
 					if ((spec->flags & OBJECT_FLAG_ALLOW_UNDER_BRIDGE) == 0) goto not_valid_below;
 					if (GetTileMaxZ(tile) + spec->height > z_start) goto not_valid_below;