(svn r25948) -Fix [FS#5796]: Make sure LinkRefresher doesn't delete the LinkGraph DeleteStaleLinks() is examining.

3 files changed, 22 insertions, 8 deletions

diff --git a/src/linkgraph/refresh.cpp b/src/linkgraph/refresh.cpp
index 53a1d28df..5fda84cea 100644
--- a/src/linkgraph/refresh.cpp
+++ b/src/linkgraph/refresh.cpp
@@ -20,8 +20,9 @@
 /**
  * Refresh all links the given vehicle will visit.
  * @param v Vehicle to refresh links for.
+ * @param allow_merge If the refresher is allowed to merge or extend link graphs.
  */
-/* static */ void LinkRefresher::Run(Vehicle *v)
+/* static */ void LinkRefresher::Run(Vehicle *v, bool allow_merge)
 {
 	/* If there are no orders we can't predict anything.*/
 	if (v->orders.list == NULL) return;
@@ -31,7 +32,7 @@
 	if (first == NULL) return;
 
 	HopSet seen_hops;
-	LinkRefresher refresher(v, &seen_hops);
+	LinkRefresher refresher(v, &seen_hops, allow_merge);
 
 	refresher.RefreshLinks(first, first, v->last_loading_station != INVALID_STATION ? 1 << HAS_CARGO : 0);
 }
@@ -59,9 +60,12 @@ bool LinkRefresher::Hop::operator<(const Hop &other) const
 /**
  * Constructor for link refreshing algorithm.
  * @param vehicle Vehicle to refresh links for.
+ * @param seen_hops Set of hops already seen. This is shared between this
+ *                  refresher and all its children.
+ * @param allow_merge If the refresher is allowed to merge or extend link graphs.
  */
-LinkRefresher::LinkRefresher(Vehicle *vehicle, HopSet *seen_hops) :
-		vehicle(vehicle), seen_hops(seen_hops), cargo(CT_INVALID)
+LinkRefresher::LinkRefresher(Vehicle *vehicle, HopSet *seen_hops, bool allow_merge) :
+		vehicle(vehicle), seen_hops(seen_hops), cargo(CT_INVALID), allow_merge(allow_merge)
 {
 	/* Assemble list of capacities and set last loading stations to 0. */
 	for (Vehicle *v = this->vehicle; v != NULL; v = v->Next()) {
@@ -190,10 +194,19 @@ void LinkRefresher::RefreshStats(const Order *cur, const Order *next)
 	if (st != NULL && next_station != INVALID_STATION && next_station != st->index) {
 		for (CapacitiesMap::const_iterator i = this->capacities.begin(); i != this->capacities.end(); ++i) {
 			/* Refresh the link and give it a minimum capacity. */
+
 			if (i->second == 0) continue;
+			CargoID c = i->first;
+
+			/* If not allowed to merge link graphs, make sure the stations are
+			 * already in the same link graph. */
+			if (!this->allow_merge && st->goods[c].link_graph != Station::Get(next_station)->goods[c].link_graph) {
+				continue;
+			}
+
 			/* A link is at least partly restricted if a
 			 * vehicle can't load at its source. */
-			IncreaseStats(st, i->first, next_station, i->second,
+			IncreaseStats(st, c, next_station, i->second,
 					(cur->GetLoadType() & OLFB_NO_LOAD) == 0 ? LinkGraph::REFRESH_UNRESTRICTED : LinkGraph::REFRESH_RESTRICTED);
 		}
 	}
diff --git a/src/linkgraph/refresh.h b/src/linkgraph/refresh.h
index aa3d8850d..21c92c4bc 100644
--- a/src/linkgraph/refresh.h
+++ b/src/linkgraph/refresh.h
@@ -23,7 +23,7 @@
  */
 class LinkRefresher {
 public:
-	static void Run(Vehicle *v);
+	static void Run(Vehicle *v, bool allow_merge = true);
 
 protected:
 	/**
@@ -87,8 +87,9 @@ protected:
 	RefitList refit_capacities; ///< Current state of capacity remaining from previous refits versus overall capacity per vehicle in the consist.
 	HopSet *seen_hops;          ///< Hops already seen. If the same hop is seen twice we stop the algorithm. This is shared between all Refreshers of the same run.
 	CargoID cargo;              ///< Cargo given in last refit order.
+	bool allow_merge;           ///< If the refresher is allowed to merge or extend link graphs.
 
-	LinkRefresher(Vehicle *v, HopSet *seen_hops);
+	LinkRefresher(Vehicle *v, HopSet *seen_hops, bool allow_merge);
 
 	void HandleRefit(const Order *next);
 	void ResetRefit();
diff --git a/src/station_cmd.cpp b/src/station_cmd.cpp
index 004202c5b..6ed0fbf94 100644
--- a/src/station_cmd.cpp
+++ b/src/station_cmd.cpp
@@ -3447,7 +3447,7 @@ void DeleteStaleLinks(Station *from)
 						 * - We could try to figure out if we've seen a consist with the same cargo on the
 						 *   same list already and if the consist can actually carry the cargo we're looking
 						 *   for. With conditional and refit orders this is not quite trivial, though. */
-						LinkRefresher::Run(v);
+						LinkRefresher::Run(v, false); // Don't allow merging. Otherwise lg might get deleted.
 						if (edge.LastUpdate() == _date) updated = true;
 					}
 					if (updated) break;