(svn r13565) -Change [FS#2077]: when invisibility is set, sprite sequences are now drawn until first non-opaque sprite is found (bit 14 not set)

This is to balance performance, code complexity and NewGRF requirements

src/rail_cmd.cpp

@@ -1847,13 +1847,13 @@ default_waypoint:
 
 		if (HasCatenaryDrawn(GetRailType(ti->tile))) DrawCatenary(ti);
 
-		/* End now if buildings are invisible */
-		if (IsInvisibilitySet(TO_BUILDINGS)) return;
-
 		foreach_draw_tile_seq(dtss, dts->seq) {
 			SpriteID image = dtss->image.sprite;
 			SpriteID pal;
 
+			/* Stop drawing sprite sequence once we meet a sprite that doesn't have to be opaque */
+			if (IsInvisibilitySet(TO_BUILDINGS) && !HasBit(image, SPRITE_MODIFIER_OPAQUE)) return;
+
 			/* Unlike stations, our default waypoint has no variation for
 			 * different railtype, so don't use the railtype offset if
 			 * no relocation is set */