Clear rail ageing data on load.

src/saveload/afterload.cpp

@@ -3152,6 +3152,15 @@ bool AfterLoadGame()
 		}
 	}
 
+	if (SlXvIsFeaturePresent(XSLFI_RAIL_AGEING)) {
+		/* remove rail aging data */
+		for (TileIndex t = 0; t < map_size; t++) {
+			if (IsPlainRailTile(t)) {
+				SB(_me[t].m7, 0, 8, 0);
+			}
+		}
+	}
+
 	/* Station acceptance is some kind of cache */
 	if (IsSavegameVersionBefore(127)) {
 		Station *st;

src/saveload/extended_ver_sl.cpp

@@ -162,6 +162,7 @@ void SlXvCheckSpecialSavegameVersions()
 		_sl_xv_feature_versions[XSLFI_HEIGHT_8_BIT] = 1;
 		_sl_xv_feature_versions[XSLFI_MIGHT_USE_PAX_SIGNALS] = 1;
 		_sl_xv_feature_versions[XSLFI_TRAFFIC_LIGHTS] = 1;
+		_sl_xv_feature_versions[XSLFI_RAIL_AGEING] = 1;
 
 		_sl_xv_feature_versions[XSLFI_TIMETABLES_START_TICKS] = 1;
 		_sl_xv_feature_versions[XSLFI_VEHICLE_REPAIR_COST] = 1;

src/saveload/extended_ver_sl.h

@@ -41,6 +41,7 @@ enum SlXvFeatureIndex {
 	XSLFI_HEIGHT_8_BIT,                           ///< Map tile height is 8 bit instead of 4 bit, but savegame version may be before this became true in trunk
 	XSLFI_MIGHT_USE_PAX_SIGNALS,                  ///< This save game might use the pax-signals feature
 	XSLFI_TRAFFIC_LIGHTS,                         ///< This save game uses road traffic lights
+	XSLFI_RAIL_AGEING,                            ///< This save game uses the rail aging patch
 	XSLFI_SPRINGPP,                               ///< This is a SpringPP game, use this for loading some settings
 
 	XSLFI_SIZE,                                   ///< Total count of features, including null feature