Merge branch 'master' into jgrpp

# Conflicts:
#	src/elrail.cpp
#	src/ground_vehicle.hpp
#	src/landscape.cpp
#	src/saveload/afterload.cpp
#	src/saveload/saveload.h
#	src/tile_cmd.h
#	src/town_cmd.cpp
#	src/tunnelbridge_cmd.cpp

src/tunnelbridge_cmd.cpp

@@ -2563,7 +2563,7 @@ void DrawBridgeMiddle(const TileInfo *ti)
 }
 
 
-static int GetSlopePixelZ_TunnelBridge(TileIndex tile, uint x, uint y)
+static int GetSlopePixelZ_TunnelBridge(TileIndex tile, uint x, uint y, bool ground_vehicle)
 {
 	int z;
 	Slope tileh = GetTilePixelSlope(tile, &z);
@@ -2572,34 +2572,27 @@ static int GetSlopePixelZ_TunnelBridge(TileIndex tile, uint x, uint y)
 	y &= 0xF;
 
 	if (IsTunnel(tile)) {
-		uint pos = (DiagDirToAxis(GetTunnelBridgeDirection(tile)) == AXIS_X ? y : x);
-
 		/* In the tunnel entrance? */
-		if (5 <= pos && pos <= 10) return z;
+		if (ground_vehicle) return z;
 	} else { // IsBridge(tile)
 		if (IsCustomBridgeHeadTile(tile)) {
 			return z + TILE_HEIGHT + (IsSteepSlope(tileh) ? TILE_HEIGHT : 0);
 		}
 
 		DiagDirection dir = GetTunnelBridgeDirection(tile);
-		uint pos = (DiagDirToAxis(dir) == AXIS_X ? y : x);
-
 		z += ApplyPixelFoundationToSlope(GetBridgeFoundation(tileh, DiagDirToAxis(dir)), &tileh);
 
 		/* On the bridge ramp? */
-		if (5 <= pos && pos <= 10) {
-			int delta;
-
+		if (ground_vehicle) {
 			if (tileh != SLOPE_FLAT) return z + TILE_HEIGHT;
 
 			switch (dir) {
 				default: NOT_REACHED();
-				case DIAGDIR_NE: delta = (TILE_SIZE - 1 - x) / 2; break;
-				case DIAGDIR_SE: delta = y / 2; break;
-				case DIAGDIR_SW: delta = x / 2; break;
-				case DIAGDIR_NW: delta = (TILE_SIZE - 1 - y) / 2; break;
+				case DIAGDIR_NE: tileh = SLOPE_NE; break;
+				case DIAGDIR_SE: tileh = SLOPE_SE; break;
+				case DIAGDIR_SW: tileh = SLOPE_SW; break;
+				case DIAGDIR_NW: tileh = SLOPE_NW; break;
 			}
-			return z + 1 + delta;
 		}
 	}
 
@@ -3063,6 +3056,29 @@ static void ChangeTileOwner_TunnelBridge(TileIndex tile, Owner old_owner, Owner
 	}
 }
 
+/**
+ * Helper to prepare the ground vehicle when entering a bridge. This get called
+ * when entering the bridge, at the last frame of travel on the bridge head.
+ * Our calling function gets called before UpdateInclination/UpdateZPosition,
+ * which normally controls the Z-coordinate. However, in the wormhole of the
+ * bridge the vehicle is in a strange state so UpdateInclination does not get
+ * called for the wormhole of the bridge and as such the going up/down bits
+ * would remain set. As such, this function clears those. In doing so, the call
+ * to UpdateInclination will not update the Z-coordinate, so that has to be
+ * done here as well.
+ * @param gv The ground vehicle entering the bridge.
+ */
+template <typename T>
+static void PrepareToEnterBridge(T *gv)
+{
+	if (HasBit(gv->gv_flags, GVF_GOINGUP_BIT)) {
+		gv->z_pos++;
+		ClrBit(gv->gv_flags, GVF_GOINGUP_BIT);
+	} else {
+		ClrBit(gv->gv_flags, GVF_GOINGDOWN_BIT);
+	}
+}
+
 /**
  * Frame when the 'enter tunnel' sound should be played. This is the second
  * frame on a tile, so the sound is played shortly after entering the tunnel
@@ -3098,7 +3114,7 @@ static VehicleEnterTileStatus VehicleEnter_TunnelBridge(Vehicle *v, TileIndex ti
 		y += offset.y;
 	}
 
-	int z = GetSlopePixelZ(x, y) - v->z_pos;
+	int z = GetSlopePixelZ(x, y, true) - v->z_pos;
 
 	if (abs(z) > 2) return VETSB_CANNOT_ENTER;
 
@@ -3188,8 +3204,7 @@ static VehicleEnterTileStatus VehicleEnter_TunnelBridge(Vehicle *v, TileIndex ti
 					Train *t = Train::From(v);
 					t->track = TRACK_BIT_WORMHOLE;
 					SetBit(t->First()->flags, VRF_CONSIST_SPEED_REDUCTION);
-					ClrBit(t->gv_flags, GVF_GOINGUP_BIT);
-					ClrBit(t->gv_flags, GVF_GOINGDOWN_BIT);
+					PrepareToEnterBridge(t);
 					break;
 				}
 
@@ -3205,9 +3220,7 @@ static VehicleEnterTileStatus VehicleEnter_TunnelBridge(Vehicle *v, TileIndex ti
 					}
 					rv->InvalidateImageCache();
 					rv->state = RVSB_WORMHOLE;
-					/* There are no slopes inside bridges / tunnels. */
-					ClrBit(rv->gv_flags, GVF_GOINGUP_BIT);
-					ClrBit(rv->gv_flags, GVF_GOINGDOWN_BIT);
+					PrepareToEnterBridge(rv);
 					break;
 				}