Don't look for ship path when the start and goal are the same.

There is no meaningful result for all out-parameters in the base
pathfinding implementation.

Author: Flamefire

external/turtle

@@ -630,13 +630,14 @@ void nofCarrier::LostWork()
 
             // Look for the shore
             const unsigned maxNodeDistance = 5;
-            std::vector<MapPoint> coastPoints =
+            const auto coastPoints =
               world->GetMatchingPointsInRadius(tmpPos, maxNodeDistance, IsCoastalAndForFigs(*world));
+            shore_path.clear();
             for(const auto& it : coastPoints)
             {
                 // 10x the node distance should be enough, otherwise it would be to far to paddle
                 const unsigned maxDistance = maxNodeDistance * 10;
-                if(world->FindShipPath(tmpPos, it, maxDistance, &shore_path, nullptr))
+                if(it == tmpPos || world->FindShipPath(tmpPos, it, maxDistance, &shore_path, nullptr))
                 {
                     // Ok let's paddle to the coast
                     rs_pos = 0;

libs/s25main/figures/nofCarrier.cpp

@@ -84,10 +84,12 @@ void ShipPathData::initHarborConnections()
             // Connections are unique
             RTTR_Assert(!helpers::contains_if(curConnections, HarborConnection::Matcher{nb.id, nb.sea}));
             curConnections.push_back(HarborConnection{nb.id, nb.sea, {}});
-            unsigned len;
+            unsigned len = 0;
+            const auto startPoint = world_.GetCoastalPoint(startHbId, nb.sea);
+            const auto nbPoint = world_.GetCoastalPoint(nb.id, nb.sea);
             const bool found =
-              world_.FindShipPath(world_.GetCoastalPoint(startHbId, nb.sea), world_.GetCoastalPoint(nb.id, nb.sea),
-                                  nb.distance, &curConnections.back().route, &len);
+              (startPoint == nbPoint)
+              || world_.FindShipPath(startPoint, nbPoint, nb.distance, &curConnections.back().route, &len);
             RTTR_Assert(found);
             RTTR_Assert(len == nb.distance);
         }

libs/s25main/pathfinding/ShipPathData.cpp

@@ -200,7 +200,14 @@ void MapSerializer::Deserialize(GameWorldBase& world, SerializedGameData& sgd, G
                     {
                         if(!helpers::contains(otherSeas, sea))
                             continue;
-                        unsigned len;
+                        unsigned len = 0;
+                        const auto startPoint = world.GetCoastalPoint(startHbId, sea);
+                        const auto nbPoint = world.GetCoastalPoint(neighbor.id, sea);
+                        if(neighbor.distance == 0 && startPoint == nbPoint)
+                        {
+                            neighbor.sea = sea;
+                            break;
+                        }
                         if(world.FindShipPath(world.GetCoastalPoint(startHbId, sea),
                                               world.GetCoastalPoint(neighbor.id, sea), neighbor.distance, nullptr, &len)
                            && len == neighbor.distance)