Index: src/elrail.cpp
===================================================================
--- src/elrail.cpp	(Revision 12066)
+++ src/elrail.cpp	(Arbeitskopie)
@@ -69,25 +69,47 @@
 #include "table/sprites.h"
 #include "table/elrail_data.h"
 
+#include "core/bitmath_func.hpp"
+
 static inline TLG GetTLG(TileIndex t)
 {
 	return (TLG)((HasBit(TileX(t), 0) << 1) + HasBit(TileY(t), 0));
 }
 
 /**
+ * Masks out TrackBits when neighbouring tiles are unelectrified
+ */
+static TrackBits MaskTrackBits(TileIndex t) {
+	TrackBits trackbits = GetTrackBits(t);
+	TrackBits neighbour_mask = TRACK_BIT_NONE;
+	for (DiagDirection d = DIAGDIR_BEGIN; d < DIAGDIR_END; d++) {
+		/* Get unelectrified neighbours, non-rail neighbours count as electrified */
+		if (GetTileType(TileAddByDiagDir(t, d)) == MP_RAILWAY && GetRailType(TileAddByDiagDir(t, d)) != RAILTYPE_ELECTRIC) {
+			neighbour_mask |= TrackdirBitsToTrackBits(DiagdirReachesTrackdirs(ReverseDiagDir(d)));
+		}
+	}
+	/* Mask out TrackBits where at least one neighbour is unelectrified
+	 * make sure, at least one TrackBit is left
+	 */
+	if ((trackbits & ~neighbour_mask) != TRACK_BIT_NONE) return trackbits & ~neighbour_mask;
+	return trackbits;
+}
+
+/**
  * Finds which Electrified Rail Bits are present on a given tile.
  * @param t tile to check
  * @param override pointer to PCP override, can be NULL
  * @return trackbits of tile if it is electrified
  */
-static TrackBits GetRailTrackBitsUniversal(TileIndex t, byte *override)
+static TrackBits GetRailTrackBitsUniversal(TileIndex t, byte *override, bool full)
 {
 	switch (GetTileType(t)) {
 		case MP_RAILWAY:
 			if (GetRailType(t) != RAILTYPE_ELECTRIC) return TRACK_BIT_NONE;
 			switch (GetRailTileType(t)) {
 				case RAIL_TILE_NORMAL: case RAIL_TILE_SIGNALS:
-					return GetTrackBits(t);
+					if (full) return GetTrackBits(t);
+					return MaskTrackBits(t);
 				case RAIL_TILE_WAYPOINT:
 					return GetRailWaypointBits(t);
 				default:
@@ -203,6 +225,7 @@
 	 * the track configuration of 2 adjacent tiles. trackconfig[0] stores the
 	 * current tile (home tile) while [1] holds the neighbour */
 	TrackBits trackconfig[TS_END];
+	TrackBits wireconfig[TS_END];
 	bool isflat[TS_END];
 	/* Note that ti->tileh has already been adjusted for Foundations */
 	Slope tileh[TS_END] = { ti->tileh, SLOPE_FLAT };
@@ -225,13 +248,14 @@
 	 * 2) on the "far" end of a bridge head (the one that connects to bridge middle),
 	 *    because that one is drawn on the bridge. Exception is for length 0 bridges
 	 *    which have no middle tiles */
-	trackconfig[TS_HOME] = GetRailTrackBitsUniversal(ti->tile, &OverridePCP);
+	wireconfig[TS_HOME] = GetRailTrackBitsUniversal(ti->tile, &OverridePCP, false);
+	trackconfig[TS_HOME] = GetRailTrackBitsUniversal(ti->tile, &OverridePCP, true);
 	/* If a track bit is present that is not in the main direction, the track is level */
 	isflat[TS_HOME] = ((trackconfig[TS_HOME] & (TRACK_BIT_HORZ | TRACK_BIT_VERT)) != 0);
 
 	AdjustTileh(ti->tile, &tileh[TS_HOME]);
 
-	for (i = DIAGDIR_NE; i < DIAGDIR_END; i++) {
+	for (i = DIAGDIR_BEGIN; i < DIAGDIR_END; i++) {
 		TileIndex neighbour = ti->tile + TileOffsByDiagDir(i);
 		Foundation foundation = FOUNDATION_NONE;
 		int k;
@@ -239,12 +263,19 @@
 		/* Here's one of the main headaches. GetTileSlope does not correct for possibly
 		 * existing foundataions, so we do have to do that manually later on.*/
 		tileh[TS_NEIGHBOUR] = GetTileSlope(neighbour, NULL);
-		trackconfig[TS_NEIGHBOUR] = GetRailTrackBitsUniversal(neighbour, NULL);
-		if (IsTunnelTile(neighbour) && i != GetTunnelBridgeDirection(neighbour)) trackconfig[TS_NEIGHBOUR] = TRACK_BIT_NONE;
+		wireconfig[TS_NEIGHBOUR] = GetRailTrackBitsUniversal(neighbour, NULL, false);
+		trackconfig[TS_NEIGHBOUR] = GetRailTrackBitsUniversal(neighbour, NULL, true);
+		if (IsTunnelTile(neighbour) && i != GetTunnelBridgeDirection(neighbour)) {
+			trackconfig[TS_NEIGHBOUR] = TRACK_BIT_NONE;
+			wireconfig[TS_NEIGHBOUR] = TRACK_BIT_NONE;
+		}
 
 		/* If the neighboured tile does not smoothly connect to the current tile (because of a foundation),
 		 * we have to draw all pillars on the current tile. */
-		if (GetPCPElevation(ti->tile, i) != GetPCPElevation(neighbour, ReverseDiagDir(i))) trackconfig[TS_NEIGHBOUR] = TRACK_BIT_NONE;
+		if (GetPCPElevation(ti->tile, i) != GetPCPElevation(neighbour, ReverseDiagDir(i))) {
+			trackconfig[TS_NEIGHBOUR] = TRACK_BIT_NONE;
+			wireconfig[TS_NEIGHBOUR] = TRACK_BIT_NONE;
+		}
 
 		isflat[TS_NEIGHBOUR] = ((trackconfig[TS_NEIGHBOUR] & (TRACK_BIT_HORZ | TRACK_BIT_VERT)) != 0);
 
@@ -254,6 +285,7 @@
 		/* We cycle through all the existing tracks at a PCP and see what
 		 * PPPs we want to have, or may not have at all */
 		for (k = 0; k < NUM_TRACKS_AT_PCP; k++) {
+			DiagDirection PCPpos = i;
 			/* Next to us, we have a bridge head, don't worry about that one, if it shows away from us */
 			if (TrackSourceTile[i][k] == TS_NEIGHBOUR &&
 			    IsBridgeTile(neighbour) &&
@@ -263,12 +295,14 @@
 
 			/* We check whether the track in question (k) is present in the tile
 			 * (TrackSourceTile) */
-			if (HasBit(trackconfig[TrackSourceTile[i][k]], TracksAtPCP[i][k])) {
+			if (HasBit(wireconfig[TrackSourceTile[i][k]], TracksAtPCP[i][k])) {
 				/* track found, if track is in the neighbour tile, adjust the number
 				 * of the PCP for preferred/allowed determination*/
-				DiagDirection PCPpos = (TrackSourceTile[i][k] == TS_HOME) ? i : ReverseDiagDir(i);
+				PCPpos = (TrackSourceTile[i][k] == TS_HOME) ? i : ReverseDiagDir(i);
 				SetBit(PCPstatus, i); // This PCP is in use
+			}
 
+			if (HasBit(trackconfig[TrackSourceTile[i][k]], TracksAtPCP[i][k])) {
 				PPPpreferred[i] &= PreferredPPPofTrackAtPCP[TracksAtPCP[i][k]][PCPpos];
 				PPPallowed[i] &= ~DisallowedPPPofTrackAtPCP[TracksAtPCP[i][k]][PCPpos];
 			}
@@ -330,7 +364,7 @@
 					/* Don't build the pylon if it would be outside the tile */
 					if (!HasBit(OwnedPPPonPCP[i], temp)) {
 						/* We have a neighour that will draw it, bail out */
-						if (trackconfig[TS_NEIGHBOUR] != 0) break;
+						if (trackconfig[TS_NEIGHBOUR] != TRACK_BIT_NONE) break;
 						continue; /* No neighbour, go looking for a better position */
 					}
 
@@ -352,7 +386,7 @@
 
 	/* Drawing of pylons is finished, now draw the wires */
 	for (t = TRACK_BEGIN; t < TRACK_END; t++) {
-		if (HasBit(trackconfig[TS_HOME], t)) {
+		if (HasBit(wireconfig[TS_HOME], t)) {
 			if (IsTunnelTile(ti->tile)) break; // drawn together with tunnel-roof (see DrawCatenaryOnTunnel())
 			byte PCPconfig = HasBit(PCPstatus, PCPpositions[t][0]) +
 				(HasBit(PCPstatus, PCPpositions[t][1]) << 1);