[devel-new-2] Choose signal bugs

[Ves]

There are some issues with choosesignals sending trains to already occupied platforms.

If you look at the swedish servergame (port 13355) at the city of Klippan, you will find a big terminus. The trains on "(3) line" tends to choose the same platform, even though it is occupied and there are others free. It creates a deadlock eventually so you will have to resolve that to see the effect. This is also an issue at the station of Vansö and the station of Träslövsläge (with line "(6) line"). The later have absolute block as choose signals, where the two former have timeinterval with telegraph. All use timeinterval with telegraph as their station signal or platform signal.

I noticed that it appears to be only when the train is parked at the platform that another train attempts to go there. If the path to the platform is occupied, it gladly accepts another platform.

This is also present in the latest build (249e6ca76e5bb3956d08ba518a0756f9038ed517).

edit: It basicly happens at all stations around the map..

[Vladki]

I have noticed something similar on the British test game. Trains that are scheduled to drive through a station with choose signals, wait at the choose signal, if the straight route is blocked, even if alternative route is clear - all the way through the station, not only to next end of choose signal, but all the way to its destination.

[Ves]

James, I dont know if you worked any particular on this thing, but it seems that the choose signal bug that is described in this thread is fixed, at least with f5e72b5c6a41f6ca064bb1d46de8e1cc29d37d16, which the swedish server is currently running. Good job!

[jamespetts]

I have just pushed a further two fixes which should deal with some issues that I have identified on the saved game relating to this issue.

[Ves]

Thanks, it appears to be fixed. However, it appears to still occur in some occasions, I will try to see if I can catch when it does!

[Vladki]

Seems fixed, at least for my game...

[jamespetts]

Thank you for reporting back - let me know if you can narrow down the conditions where it recurs so that I can remedy it.

[Ves]

This appears to be extremely difficult! If I save the game when I know this happens, upon reloading, the train will stop at the choose signal or find an alternate platform!

[jamespetts]

How very odd.

[Ves]

If you play around with the trains on the track circuit block line, opening their schedules so they keep running, you will eventually witness the bug. 

[jamespetts]

It is very difficult to reproduce bugs in this way, as, in order to fix a bug, I usually have to be able to reproduce it many times over in exactly the same circumstances to check whether each attempted fix works.

Are you able to identify a specific sequence of steps from a given saved game that will reliably reproduce the issue?

[Ves]

Ok, I might have found a way to reproduce something:

Load the savegame http://simutrans-germany.com/files/upload/Track_circuit_block_issues_-_TimeTel-Abso-Trackcirc_2.sve (same as previously published one):
* Follow the two trains leaving "Träslövsläge station"
* A deadlock is occuring at "Träslövsläge External Station". Resolve that by clicking with the unreservertool on the eastern platform. The second northgoing train should now enter the platform.
* Now look at the train which is further north, pointing southward. It is stuck behind a track circuit block signal. Get it to move again by opening its schedule WHILE THE OTHER TRAIN IS STILL ON THE WESTERN PLATFORM, however, late enough so the train on the platform manages to leave before this train arrives. If you send it away after the other train have left, it might be stuck there due to a directional reservation on the track and the signals "blinking" between clear and danger.

Now I have gotten two different results, so keep track of both
* When the track is clear, the train which is called "(3) Se_L(II)_1900") will go to the end station, "Brändön East Station". Remember this place as if the other deadlock do not occur, it should occur here.
* Go back and look at "Träslövsläge Station", and "(1) Se_L(II)_1900" should choose an occupied platform.

[Junna]

This should be reproducible at the station it is centred upon here

Spurious reservations will also appear at the station, trains on the other end of the line will have reservations suddenly appear at the station as well, this seems to keep repeating so should be reproducible in the save, after spurious reservations are cancelled, new will appear. Also, the end of chose signals are ignored, also leading to deadlocks. 

http://www.mediafire.com/file/ruk4eu2t22p5zlx/ders5911x.rar

save

https://www.mediafire.com/?ruk4eu2t22p5zlx

pak

[jamespetts]

I think that I have fixed the extraneous reservations issue, but I have not had a chance to look at the choose signals yet. Can you confirm that extraneous reservations now no longer occur?

[Ves]

If you meant on my map, Im sorry to say that I can not notice much difference. Trains still get stuck behind the signals and there is a directional reserved platform which is unable to resolve by clicking on it.

[jamespetts]

The issue that I fixed was trains not clearing their reservations fully when leaving a platform in some cases. I have not had a chance to look at the other issues yet.

[jamespetts]

I think that I have now fixed a, even if not the, choose signal issue. Would you be able to re-test to confirm whether any issue remains? I could not find any instances of trains ignoring end of choose signals in Junna's map, and Ves's map seems to work correctly after the application of the fix, albeit in only a brief test.

[Ves]

I have been checking lately, and although it appears to work better, there are still some of the same issues:

savegame:
http://simutrans-germany.com/files/upload/Choose_signal_bug_2.sve

Just wait at the station and "(6) Se_A(II)_1900" will choose an occupied platform.

[Vladki]

I thought I have resolved some deadlocks by putting end-of-choose signs at brandon branch and traslovslage external stations, but alas, there is a heads on collision again...

[jamespetts]

I am currently reviewing old bug reports and I notice that this one appears to have no reported resolution. May I ask whether this can still be reproduced?

[Junna]

I have been unable to reproduce any of these lately (4 in-game months without any deadlocks apart from two I caused myself), though I wouldn't guarantee that they are gone.

[jamespetts]

Thank you for letting me know; I shall mark this as fixed in that case for now. Please do post a new report if this recurs.