From 5bc5d43ffbac999a5b8eef23230ec49c4a42f42d Mon Sep 17 00:00:00 2001
From: Jonathan G Rennison <j.g.rennison@gmail.com>
Date: Sat, 13 Feb 2016 16:51:35 +0000
Subject: [PATCH] Add checks to prevent coupling free wagon chains of different
 owners.

---
 src/train_cmd.cpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/train_cmd.cpp b/src/train_cmd.cpp
index 9426889aa7..d1448e60e6 100644
--- a/src/train_cmd.cpp
+++ b/src/train_cmd.cpp
@@ -660,7 +660,8 @@ static CommandCost CmdBuildRailWagon(TileIndex tile, DoCommandFlag flags, const
 					w->IsFreeWagon() &&             ///< A free wagon chain
 					w->engine_type == e->index &&   ///< Same type
 					w->First() != v &&              ///< Don't connect to ourself
-					!(w->vehstatus & VS_CRASHED)) { ///< Not crashed/flooded
+					!(w->vehstatus & VS_CRASHED) && ///< Not crashed/flooded
+					w->owner == v->owner) {         ///< Same owner
 				DoCommand(0, v->index | 1 << 20, w->Last()->index, DC_EXEC, CMD_MOVE_RAIL_VEHICLE);
 				break;
 			}
@@ -676,7 +677,8 @@ static void NormalizeTrainVehInDepot(const Train *u)
 	const Train *v;
 	FOR_ALL_TRAINS(v) {
 		if (v->IsFreeWagon() && v->tile == u->tile &&
-				v->track == TRACK_BIT_DEPOT) {
+				v->track == TRACK_BIT_DEPOT &&
+				v->owner == u->owner) {
 			if (DoCommand(0, v->index | 1 << 20, u->index, DC_EXEC,
 					CMD_MOVE_RAIL_VEHICLE).Failed())
 				break;
@@ -810,7 +812,7 @@ static Train *FindGoodVehiclePos(const Train *src)
 
 	Train *dst;
 	FOR_ALL_TRAINS(dst) {
-		if (dst->IsFreeWagon() && dst->tile == tile && !(dst->vehstatus & VS_CRASHED)) {
+		if (dst->IsFreeWagon() && dst->tile == tile && !(dst->vehstatus & VS_CRASHED) && dst->owner == src->owner) {
 			/* check so all vehicles in the line have the same engine. */
 			Train *t = dst;
 			while (t->engine_type == eng) {