Fix extended order info not being saved for vehicle current order.

This fixes desync and related issues when loading savegames where
extended order info is used.

src/order_base.h

@@ -45,6 +45,8 @@ private:
 	friend const struct SaveLoad *GetOrderDescription();                 ///< Saving and loading of orders.
 	friend void Load_ORDX();                                             ///< Saving and loading of orders.
 	friend void Save_ORDX();                                             ///< Saving and loading of orders.
+	friend void Load_VEOX();                                             ///< Saving and loading of orders.
+	friend void Save_VEOX();                                             ///< Saving and loading of orders.
 
 	uint8 type;           ///< The type of order + non-stop flags
 	uint8 flags;          ///< Load/unload types, depot order/action types.

src/saveload/extended_ver_sl.cpp

@@ -45,7 +45,7 @@ std::vector<uint32> _sl_xv_discardable_chunk_ids;           ///< list of chunks
 static const uint32 _sl_xv_slxi_chunk_version = 0;          ///< current version os SLXI chunk
 
 const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
-	{ XSLFI_CARGO_TYPE_ORDERS,      XSCF_NULL,                1,   1, "cargo_type_orders",         NULL, NULL, "ORDX"      },
+	{ XSLFI_CARGO_TYPE_ORDERS,      XSCF_NULL,                2,   2, "cargo_type_orders",         NULL, NULL, "ORDX,VEOX" },
 
 	{ XSLFI_NULL, XSCF_NULL, 0, 0, NULL, NULL, NULL, NULL },// This is the end marker
 };

src/saveload/vehicle_sl.cpp

@@ -934,6 +934,33 @@ static void Ptrs_VEHS()
 	}
 }
 
+const SaveLoad *GetOrderExtraInfoDescription();
+
+void Save_VEOX()
+{
+	/* save extended order info for vehicle current order */
+	Vehicle *v;
+	FOR_ALL_VEHICLES(v) {
+		if (v->current_order.extra) {
+			SlSetArrayIndex(v->index);
+			SlObject(v->current_order.extra.get(), GetOrderExtraInfoDescription());
+		}
+	}
+}
+
+void Load_VEOX()
+{
+	/* load extended order info for vehicle current order */
+	int index;
+	while ((index = SlIterateArray()) != -1) {
+		Vehicle *v = Vehicle::GetIfValid(index);
+		assert(v != NULL);
+		v->current_order.AllocExtraInfo();
+		SlObject(v->current_order.extra.get(), GetOrderExtraInfoDescription());
+	}
+}
+
 extern const ChunkHandler _veh_chunk_handlers[] = {
-	{ 'VEHS', Save_VEHS, Load_VEHS, Ptrs_VEHS, NULL, CH_SPARSE_ARRAY | CH_LAST},
+	{ 'VEHS', Save_VEHS, Load_VEHS, Ptrs_VEHS, NULL, CH_SPARSE_ARRAY},
+	{ 'VEOX', Save_VEOX, Load_VEOX, NULL,      NULL, CH_SPARSE_ARRAY | CH_LAST},
 };