After some time spent on building my transportation network I discovered a very annoying bug. Complete list of strange behaviors:
1. Some trains, that should carry goods are leaving supplier's siding empty (with payload set at 100% in schedule!) then going to random (!) point in schedule and reversing, then going back to the supplier.
2. Other trains take the cargo but aren't going to the factory's customer - they are also going to random point and reversing to supplier.
3. Some trains are reversing twice (!) doing the loop before reaching receiver's siding.
4. I've even seen a train, that couldn't leave it's cargo at receiver - it took the payload all way back to the supplier.
What's going on? If someone wants to see it I can upload the .sve and whole pakset to Dropbox.
Please upload! What version of simutrans do you use?
Here you are. (https://www.dropbox.com/s/rv1jm978emnwzq5/pak128.mix.hh.zip?dl=0) Archive is containing a .sve and complete pakset. Problem concerns trains № VN 1118, VN 1119, VN 1120, VN 1121, VN 1122.
The convoys seem to fail to register passing some way points in their schedule but continue along the specified path as if they have. As such it does not unload when it reaches the destination (stop) but instead thinks it needs to back track to the skipped waypoint. Almost certainly a bug relating to waypoints.
That seems reasonable. It is the first time I've heard it happen with trains, though. 4 may however be something else. I've seen some oddities with cargo destinations recently (although the build might have been a bit stale), but it disappeared by itself and I have not seen it again.
Sorry for the late reply, but this should be fixed now in r8075.