--- a/chunnel.pre.patch	2021-01-03 22:30:58.721115549 +0100
+++ b/chunnel.pre.patch	2021-01-03 22:30:58.721115549 +0100
@@ -790,7 +790,7 @@
  	Slope end_tileh;
  	for (;;) {
 @@ -672,13 +675,69 @@ CommandCost CmdBuildTunnel(TileIndex start_tile, DoCommandFlag flags, uint32 p1,
- 		if (!IsValidTile(end_tile)) return_cmd_error(STR_ERROR_TUNNEL_THROUGH_MAP_BORDER);
+ 
  		end_tileh = GetTileSlope(end_tile, &end_z);
  
 -		if (start_z == end_z) break;
@@ -1015,9 +1015,9 @@
  	if (v->type == VEH_EFFECT) {
  		/* Check whether the vehicle shall be transparent/invisible due to GUI settings.
 @@ -1139,7 +1147,7 @@ void ViewportAddVehicles(DrawPixelInfo *dpi)
- 			const Vehicle *v = _vehicle_viewport_hash[x + y]; // already masked & 0xFFF
  
  			while (v != nullptr) {
+ 				if (LayerIndex(v->tile) == dpi->layer)
 -				if (!(v->vehstatus & VS_HIDDEN) &&
 +				if (v->IsDrawn() &&
  						l <= v->coord.right &&