Fix re-routing of unrelated cargo when removing invalidated link graph flow

src/station_cmd.cpp

@@ -4094,6 +4094,31 @@ void RerouteCargo(Station *st, CargoID c, StationID avoid, StationID avoid2)
 	}
 }
 
+/**
+ * Reroute cargo of type c from source at station st or in any vehicles unloading there.
+ * Make sure the cargo's new next hop is neither "avoid" nor "avoid2".
+ * @param st Station to be rerouted at.
+ * @param c Type of cargo.
+ * @param source Source station.
+ * @param avoid Original next hop of cargo, avoid this.
+ * @param avoid2 Another station to be avoided when rerouting.
+ */
+void RerouteCargoFromSource(Station *st, CargoID c, StationID source, StationID avoid, StationID avoid2)
+{
+	GoodsEntry &ge = st->goods[c];
+
+	/* Reroute cargo in station. */
+	ge.cargo.RerouteFromSource(UINT_MAX, &ge.cargo, source, avoid, avoid2, &ge);
+
+	/* Reroute cargo staged to be transferred. */
+	for (Vehicle *v : st->loading_vehicles) {
+		for (; v != nullptr; v = v->Next()) {
+			if (v->cargo_type != c) continue;
+			v->cargo.RerouteFromSource(UINT_MAX, &v->cargo, source, avoid, avoid2, &ge);
+		}
+	}
+}
+
 btree::btree_set<VehicleID> _delete_stale_links_vehicle_cache;
 
 void ClearDeleteStaleLinksVehicleCache()