[0.14.22] [Twinsen] Locked belts allow item passage when replaced

[Robb]

When experimenting with belts and the circuit network, I experienced some unexpected behavior when constructing a different variety of belt over another belt locked by a circuit condition. Items were able to enter the belt from other belts and, when repeatedly replaced, pass through the belt and exit on the other end.

Here is a video demonstrating the issue:

Link

https://youtu.be/kov4ppoxQnY

I have attached the world save used in the video that I have tested a setup in multiple times with the same result. I have not included a log file as I see no information contained in the log related to belts or circuit conditions, and the issue does not cause corruption or crashing.

belt_bug_demo.zip

Save file

(894.33 KiB) Downloaded 79 times

I have not attempted to use a logistic network condition in place of a circuit condition, nor attempted this on a straight belt instead of a corner.

I have performed an advanced search using the phrase '+belt +circuit' and I have not found my issue mentioned elsewhere. No mods are enabled (other than the default Base Mod).

On a side note, I originally typed up a more in-depth description of the issue, but when I clicked 'save draft,' the draft was not saved and I was brought to a login page instead. I lost all that I had typed up, and I would rather not retype it. The issue saving has not occurred a second time, and I am certain that I was logged in before clicking save draft.

[The Eriksonn]

I belive that the belt connect to the network 1 tick after it is placed ,resulting in a 1 tick jump of the item.

[Robb]

I agree. This could probably be solved by starting belts disabled when they are replaced and only enabling them once they connect to the circuit network, but that might cause unnecessary lag when running along replacing the belts of large belt buses.

I tested this a bit more, and the same behavior occurs for vertical and horizontal belts, not just corners. Also, items on both sides of the belt are nudged the same distance. The issue does not occur, however, when construction bots place down a locked belt via blueprint. I guess the entity is created with all of its settings from the start in that case, whereas the settings are not copied over until later with belt replacing.

[Klonan]

Thanks for the report,

I have reproduced the issue in 0.15:

[Twinsen]

Belts deactivate 1 tick after creation. It's done to be consistent with most things in the circuit network that take exactly 1 tick to react.
I'll keep it in my low priority list and maybe fix it later if there is some gameplay detriment to make this really feel like a bug.

[Robb]

Thank you for your time. I'm glad I could help.