Bump version, set semaphore/pbs/exit sig state on upgrade.

src/saveload/afterload.cpp

@@ -2968,6 +2968,17 @@ bool AfterLoadGame()
 #endif
 	}
 
+	if (SlXvIsFeaturePresent(XSLFI_SIG_TUNNEL_BRIDGE, 1, 1)) {
+		/* set the semaphore bit to match what it would have been in v1 */
+		/* clear the PBS bit, update the end signal state */
+		for (TileIndex t = 0; t < map_size; t++) {
+			if (IsTileType(t, MP_TUNNELBRIDGE) && GetTunnelBridgeTransportType(t) == TRANSPORT_RAIL && HasWormholeSignals(t)) {
+				SetTunnelBridgeSemaphore(t, _cur_year < _settings_client.gui.semaphore_build_before);
+				SetTunnelBridgePBS(t, false);
+				UpdateSignalsOnSegment(t, INVALID_DIAGDIR, GetTileOwner(t));
+			}
+		}
+	}
 
 	/* Station acceptance is some kind of cache */
 	if (IsSavegameVersionBefore(127)) {

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_SIG_TUNNEL_BRIDGE, XSCF_NULL, 1, 1, "signal_tunnel_bridge", NULL, NULL, NULL },
+	{ XSLFI_SIG_TUNNEL_BRIDGE,      XSCF_NULL,                2,   2, "signal_tunnel_bridge",      NULL, NULL, NULL        },
 	{ XSLFI_NULL, XSCF_NULL, 0, 0, NULL, NULL, NULL, NULL },// This is the end marker
 };