(svn r18647) -Fix: [YAPP] A train inside a station was not always found when checking for trains on a reserved path.

3 files changed, 19 insertions, 5 deletions

diff --git a/src/pbs.cpp b/src/pbs.cpp
index adae29e5b..9619b201b 100644
--- a/src/pbs.cpp
+++ b/src/pbs.cpp
@@ -262,7 +262,7 @@ static Vehicle *FindTrainOnTrackEnum(Vehicle *v, void *data)
  * @param train_on_res Is set to a train we might encounter
  * @returns The last tile of the reservation or the current train tile if no reservation present.
  */
-PBSTileInfo FollowTrainReservation(const Train *v, bool *train_on_res)
+PBSTileInfo FollowTrainReservation(const Train *v, Vehicle **train_on_res)
 {
 	assert(v->type == VEH_TRAIN);
 
@@ -274,7 +274,21 @@ PBSTileInfo FollowTrainReservation(const Train *v, bool *train_on_res)
 	FindTrainOnTrackInfo ftoti;
 	ftoti.res = FollowReservation(v->owner, GetRailTypeInfo(v->railtype)->compatible_railtypes, tile, trackdir);
 	ftoti.res.okay = IsSafeWaitingPosition(v, ftoti.res.tile, ftoti.res.trackdir, true, _settings_game.pf.forbid_90_deg);
-	if (train_on_res != NULL) *train_on_res = HasVehicleOnPos(ftoti.res.tile, &ftoti, FindTrainOnTrackEnum);
+	if (train_on_res != NULL) {
+		FindVehicleOnPos(ftoti.res.tile, &ftoti, FindTrainOnTrackEnum);
+		if (ftoti.best != NULL) *train_on_res = ftoti.best->First();
+		if (*train_on_res == NULL && IsRailStationTile(ftoti.res.tile)) {
+			/* The target tile is a rail station. The track follower
+			 * has stopped on the last platform tile where we haven't
+			 * found a train. Also check all previous platform tiles
+			 * for a possible train. */
+			TileIndexDiff diff = TileOffsByDiagDir(TrackdirToExitdir(ReverseTrackdir(ftoti.res.trackdir)));
+			for (TileIndex st_tile = ftoti.res.tile + diff; *train_on_res == NULL && IsCompatibleTrainStationTile(st_tile, ftoti.res.tile); st_tile += diff) {
+				FindVehicleOnPos(st_tile, &ftoti, FindTrainOnTrackEnum);
+				if (ftoti.best != NULL) *train_on_res = ftoti.best->First();
+			}
+		}
+	}
 	return ftoti.res;
 }
 
diff --git a/src/pbs.h b/src/pbs.h
index f1248364a..ec24477af 100644
--- a/src/pbs.h
+++ b/src/pbs.h
@@ -34,7 +34,7 @@ struct PBSTileInfo {
 	PBSTileInfo(TileIndex _t, Trackdir _td, bool _okay) : tile(_t), trackdir(_td), okay(_okay) {}
 };
 
-PBSTileInfo FollowTrainReservation(const Train *v, bool *train_on_res = NULL);
+PBSTileInfo FollowTrainReservation(const Train *v, Vehicle **train_on_res = NULL);
 bool IsSafeWaitingPosition(const Train *v, TileIndex tile, Trackdir trackdir, bool include_line_end, bool forbid_90deg = false);
 bool IsWaitingPositionFree(const Train *v, TileIndex tile, Trackdir trackdir, bool forbid_90deg = false);
 
diff --git a/src/train_cmd.cpp b/src/train_cmd.cpp
index 5fbd2278f..d2c64bc0a 100644
--- a/src/train_cmd.cpp
+++ b/src/train_cmd.cpp
@@ -2872,14 +2872,14 @@ bool TryPathReserve(Train *v, bool mark_as_stuck, bool first_tile_okay)
 		}
 	}
 
-	bool other_train = false;
+	Vehicle *other_train = NULL;
 	PBSTileInfo origin = FollowTrainReservation(v, &other_train);
 	/* The path we are driving on is alread blocked by some other train.
 	 * This can only happen in certain situations when mixing path and
 	 * block signals or when changing tracks and/or signals.
 	 * Exit here as doing any further reservations will probably just
 	 * make matters worse. */
-	if (other_train && v->tile != origin.tile) {
+	if (other_train != NULL && other_train->index != v->index) {
 		if (mark_as_stuck) MarkTrainAsStuck(v);
 		return false;
 	}