Reloading changes convoy reversing/shunting behaviour

[Matthew]

Steps to reproduce

1. Open a new instance of Simutrans-Extended (this part is critical).
2. Load this save game from B-B and immediately pause.
3. You should see Noranavan Train Sidings at (4045,215) as the Caledonian Railway with train NPP  (Noranavan—Ballpeth Passenger) scheduled to depart soon. If convoy tooltips are not on, turn them on.
4. Note how long train NPP takes to reverse/shunt. It is just over 5 minutes.
4. In the same Sim-Ex instance, reload the save game.
5. Return to Noranavan Train Sidings and compare the reversing/shunting times.

Expected results

Trains take the same amount of time in the reloaded game as they do in the loaded game.

Actual results

In the reloaded game, reversing/shunting is instant.

Observations

This is not a recent phenomenon. I believe this bug has existed for at least a year (possibly as long ago as this 2019 bug report and very likely as long as my comment in 2020). But it took me a long time to reproduce it because I thought it was an online vs offline bug. On a typical server, most players will see 'reloads' under this behaviour. I am still not certain that I have caught all the conditions that trigger it. I suspect that the convoys' bidirectional status may be relevant (see the last linked thread).

This might well be the cause of the fact that the players are instantly desynced if they join an online server after starting the client with the demo game.

I have only reproduced this on trains, but I believe it affects all modes.

If this bug is fixed, it will temporarily cause chaos in everyone's games because our timetables are based on instantly reversing. Some newer players may never have seen trains reverse as intended.... 

[Ranran]

Observations

This is not a recent phenomenon. I believe this bug has existed for at least a year (possibly as long ago as this 2019 bug report and very likely as long as my comment in 2020). But it took me a long time to reproduce it because I thought it was an online vs offline bug. On a typical server, most players will see 'reloads' under this behaviour. I am still not certain that I have caught all the conditions that trigger it. I suspect that the convoys' bidirectional status may be relevant (see the last linked thread).

This might well be the cause of the fact that the players are instantly desynced if they join an online server after starting the client with the demo game.

I have only reproduced this on trains, but I believe it affects all modes.

If this bug is fixed, it will temporarily cause chaos in everyone's games because our timetables are based on instantly reversing. Some newer players may never have seen trains reverse as intended.... 

What is the rationale?

To conclude, this bug appears to date back to when the convoy reversing delay feature was brought to extended, i.e. 13 years ago, and last linked thread is compretely irrelevant.

Submitting a bug report is greatly appreciated. It's your credit to discover such a long lurking bug.
However please don't put unsubstantiated speculations in bug reports.

This is not the place to show uncertain predictions like horse race predictions. It's worse than nothing written. The rationale that it is relevant should be clarified. It is like a chaff that makes it harder to find location of the bug.
Well, it may also be self-discipline.

Your post makes it look as though my old patch may have caused the bug. I don't want to be irresponsible like him and ignore the bugs I spawned. So I looked into this. And I dare to mention this because I was once again (e.g. (1)(2)) misled by your false assumptions.



When someone speculates on the cause of a bug, we expect him to have a basis for saying so. That's why I dared to investigate the unlikely possibilities...
The most likely guess, just looking at the bug report, is that there is no code to store the reversing_time/reverse_delay, or it doesn't load(restore) it from saved game correctly. That's the first possibility to look into. At least it's clear that it's not working.



Second, on what basis did you deduce when it started?
Just get experimental 12.900 and an old britain-pak from http://bridgewater-brunel.me.uk/downloads/ and test it to confirm it's an old bug.

This might well be the cause of the fact that the players are instantly desynced if they join an online server after starting the client with the demo game.

On what basis did you say they are related?
I'm sure they are unrelated because some people have already posted evidence-based speculation about it but remember what I wrote in this post.