Fix savegames with incorrect signal always reserve through bits

See: #620

src/saveload/afterload.cpp

@@ -4347,7 +4347,8 @@ bool AfterLoadGame()
 	extern void YapfCheckRailSignalPenalties();
 	YapfCheckRailSignalPenalties();
 
-	UpdateExtraAspectsVariable();
+	bool update_always_reserve_through = SlXvIsFeaturePresent(XSLFI_REALISTIC_TRAIN_BRAKING, 8, 10);
+	UpdateExtraAspectsVariable(update_always_reserve_through);
 
 	if (_networking && !_network_server) {
 		SlProcessVENC();

src/signal.cpp

@@ -1892,7 +1892,7 @@ static bool DetermineExtraAspectsVariable()
 	return changed;
 }
 
-void UpdateExtraAspectsVariable()
+void UpdateExtraAspectsVariable(bool update_always_reserve_through)
 {
 	std::array<NewSignalStyleMapping, MAX_NEW_SIGNAL_STYLES> new_mapping;
 	DetermineSignalStyleMapping(new_mapping);
@@ -1915,6 +1915,8 @@ void UpdateExtraAspectsVariable()
 		if (_extra_aspects > 0) UpdateAllSignalAspects();
 		UpdateAllBlockSignals();
 		MarkWholeScreenDirty();
+	} else if (update_always_reserve_through) {
+		UpdateAllSignalReserveThroughBits();
 	}
 }
 

src/signal_func.h

@@ -195,7 +195,7 @@ void UpdateLookaheadCombinedNormalShuntSignalDeferred(TileIndex tile, Trackdir t
 void FlushDeferredAspectUpdates();
 void FlushDeferredDetermineCombineNormalShuntMode(Train *v);
 void UpdateAllSignalAspects();
-void UpdateExtraAspectsVariable();
+void UpdateExtraAspectsVariable(bool update_always_reserve_through = false);
 void InitialiseExtraAspectsVariable();
 bool IsRailSpecialSignalAspect(TileIndex tile, Track track);
 

src/sl/extended_ver_sl.cpp

@@ -157,7 +157,7 @@ const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
 	{ XSLFI_ANIMATED_TILE_EXTRA,              XSCF_NULL,                1,   1, "animated_tile_extra",              nullptr, nullptr, nullptr          },
 	{ XSLFI_NEWGRF_INFO_EXTRA,                XSCF_NULL,                1,   1, "newgrf_info_extra",                nullptr, nullptr, nullptr          },
 	{ XSLFI_INDUSTRY_CARGO_ADJ,               XSCF_IGNORABLE_UNKNOWN,   1,   1, "industry_cargo_adj",               nullptr, nullptr, nullptr          },
-	{ XSLFI_REALISTIC_TRAIN_BRAKING,          XSCF_NULL,               10,  10, "realistic_train_braking",          nullptr, nullptr, "VLKA"           },
+	{ XSLFI_REALISTIC_TRAIN_BRAKING,          XSCF_NULL,               11,  11, "realistic_train_braking",          nullptr, nullptr, "VLKA"           },
 	{ XSLFI_INFLATION_FIXED_DATES,            XSCF_IGNORABLE_ALL,       1,   1, "inflation_fixed_dates",            nullptr, nullptr, nullptr          },
 	{ XSLFI_WATER_FLOODING,                   XSCF_NULL,                2,   2, "water_flooding",                   nullptr, nullptr, nullptr          },
 	{ XSLFI_MORE_HOUSES,                      XSCF_NULL,                2,   2, "more_houses",                      nullptr, nullptr, nullptr          },