Index: train_cmd.c
===================================================================
--- train_cmd.c	(r‚vision 4906)
+++ train_cmd.c	(copie de travail)
@@ -112,6 +112,7 @@
 	if (v->u.rail.cached_power != power) {
 		v->u.rail.cached_power = power;
 		InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
+		InvalidateWindow(WC_VEHICLE_VIEW, v->index);
 	}
 }
 
@@ -1495,6 +1496,7 @@
 static void ReverseTrainSwapVeh(Vehicle *v, int l, int r)
 {
 	Vehicle *a, *b;
+	bool dochange = true;
 
 	/* locate vehicles to swap */
 	for (a = v; l != 0; l--) a = a->next;
@@ -1538,7 +1540,16 @@
 	}
 
 	/* Update train's power incase tiles were different rail type */
-	TrainPowerChanged(v);
+	/* but don't do it if the train is now going in depot */
+	if (IsTileDepotType(v->tile, TRANSPORT_RAIL)) {
+		for (a = v; a != NULL; a = a->next) {
+			if (a->u.rail.track != 0x80 || a->tile != v->tile) {
+				dochange = false;
+				break;
+			}
+		}
+	}
+	if (dochange) TrainPowerChanged(v);
 }
 
 /* Check if the vehicle is a train and is on the tile we are testing */
@@ -2045,6 +2056,9 @@
 {
 	Vehicle *u;
 
+	/* the train must stay in depot if it doesn't have power */
+	if (v->u.rail.track == 0x80 && v->u.rail.cached_power == 0) return true;
+
 	// bail out if not all wagons are in the same depot or not in a depot at all
 	for (u = v; u != NULL; u = u->next) {
 		if (u->u.rail.track != 0x80 || u->tile != v->tile) return false;
@@ -2947,7 +2961,7 @@
 				if (!(r&0x4)) {
 					v->tile = gp.new_tile;
 
-					if (GetTileRailType(gp.new_tile, chosen_track) != GetTileRailType(gp.old_tile, v->u.rail.track)) {
+					if (!IsTileDepotType(gp.new_tile, TRANSPORT_RAIL) && GetTileRailType(gp.new_tile, chosen_track) != GetTileRailType(gp.old_tile, v->u.rail.track)) {
 						TrainPowerChanged(GetFirstVehicleInChain(v));
 					}
 
@@ -3367,10 +3381,21 @@
 
 void TrainEnterDepot(Vehicle *v, TileIndex tile)
 {
+	bool last = v->next == NULL;
+
 	UpdateSignalsOnSegment(tile, GetRailDepotDirection(tile));
 
 	if (!IsFrontEngine(v)) v = GetFirstVehicleInChain(v);
 
+	if (last) {
+		TrainPowerChanged(v);
+		/* if the vehicle now have no power, change his order so it will be stopped */
+		if (v->u.rail.cached_power == 0) {
+			v->current_order.type = OT_GOTO_DEPOT;
+			SETBIT(v->current_order.flags, OFB_HALT_IN_DEPOT);
+		}
+	}
+
 	VehicleServiceInDepot(v);
 
 	InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
Index: rail_cmd.c
===================================================================
--- rail_cmd.c	(r‚vision 4906)
+++ rail_cmd.c	(copie de travail)
@@ -29,6 +29,7 @@
 #include "newgrf.h"
 #include "newgrf_callbacks.h"
 #include "newgrf_station.h"
+#include "train.h"
 
 const byte _track_sloped_sprites[14] = {
 	14, 15, 22, 13,
@@ -864,11 +865,28 @@
 
 		/* Update build vehicle window related to this depot */
 		if (IsTileDepotType(tile, TRANSPORT_RAIL)) {
+			Vehicle *v;
 			Window *w = FindWindowById(WC_BUILD_VEHICLE, tile);
 			if (w != NULL) {
 				WP(w,buildtrain_d).railtype = totype;
 				SetWindowDirty(w);
 			}
+
+			/* Update vehicule power */
+			FOR_ALL_VEHICLES(v) {
+				if (v->type == VEH_Train && IsFrontEngine(v) && v->tile == tile && v->u.rail.track == 0x80) {
+					Vehicle *u;
+					bool dochange = true;
+					for (u = v; u != NULL; u = u->next) {
+						if (u->u.rail.track != 0x80 || u->tile != v->tile) {
+							dochange = false;
+							break;
+						}
+					}
+					if (dochange) TrainPowerChanged(v);
+				}
+			}
+			InvalidateWindow(WC_VEHICLE_DEPOT, tile);
 		}
 	}
 
Index: train_gui.c
===================================================================
--- train_gui.c	(r‚vision 4906)
+++ train_gui.c	(copie de travail)
@@ -445,6 +445,10 @@
 			/* Draw the pretty flag */
 			DrawSprite(v->vehstatus & VS_STOPPED ? SPR_FLAG_VEH_STOPPED : SPR_FLAG_VEH_RUNNING, x + 15, y);
 
+			/* Draw a lock if the train can't be started */
+			if (v->vehstatus & VS_STOPPED && v->u.rail.cached_power == 0)
+				DrawSprite(SPR_LOCK,  x + 15, y);
+
 			y += 14;
 		}
 	}
@@ -594,7 +598,8 @@
 		break;
 
 	case -2: // click start/stop flag
-		DoCommandP(v->tile, v->index, 0, NULL, CMD_START_STOP_TRAIN | CMD_MSG(STR_883B_CAN_T_STOP_START_TRAIN));
+		if (!(v->vehstatus & VS_STOPPED && v->u.rail.cached_power == 0))
+			DoCommandP(v->tile, v->index, 0, NULL, CMD_START_STOP_TRAIN | CMD_MSG(STR_883B_CAN_T_STOP_START_TRAIN));
 		break;
 	}
 }
@@ -917,6 +922,10 @@
 
 			SETBIT(w->disabled_state, 12);
 
+			/* disable start button if stopped in depot and no power */
+			if (v->vehstatus & VS_STOPPED && v->u.rail.track == 0x80 && v->u.rail.cached_power == 0)
+				SETBIT(w->disabled_state, 5);
+
 			/* See if any vehicle can be refitted */
 			for (u = v; u != NULL; u = u->next) {
 				if (EngInfo(u->engine_type)->refit_mask != 0 ||
@@ -983,6 +992,9 @@
 
 		/* draw the flag plus orders */
 		DrawSprite(v->vehstatus & VS_STOPPED ? SPR_FLAG_VEH_STOPPED : SPR_FLAG_VEH_RUNNING, 2, w->widget[5].top + 1);
+		/* draw a lock if the train can't be started */
+		if (v->vehstatus & VS_STOPPED && v->vehstatus & VS_HIDDEN && v->u.rail.cached_power == 0)
+			DrawSprite(SPR_LOCK, 2, w->widget[5].top + 1);
 		DrawStringCenteredTruncated(w->widget[5].left + 8, w->widget[5].right, w->widget[5].top + 1, str, 0);
 		DrawWindowViewport(w);
 	}	break;