[0.17.11] Disabled Inserter unloads on to train

[almania]

Inserters with items in hand will unload on to an arriving cargo wagon, even if disabled.

Demonstration paste: https://pastebin.com/ee5A4dvA, requires Creative Mod, but same behaviour definitely occurs in vanilla.

I believe this is new to 0.17, as it's breaking significant parts of my train network. Cannot test 0.16 works however, due to a separate crash on attempting to downgrade that you might like to know about.

I do understand the interaction here - that once an inserter has begun a swing it does not normally cancel, however this makes trains with unfiltered wagons just about unusable for mixed stops, which makes generic trains very hard to use indeed.

Currently looking at hacking in extracting inserters to pull out trash inadvertently loaded, but yikes.

Thanks.

[Vegemeister]

Something that fixes your particular test case is to limit the inserter stack size to 10, and add a 4th inserter. That makes the overall stack size 40, which divides evenly into the inventory capacity of the train. That way, inserters are never left with items in their hands when the train leaves. This is a somewhat brittle solution, however, because if a chest ever runs dry while a train is in the station, the inserters will get out of sync.

IDK if this works for your actual use case or just the test.

In order to make the game work the way you want it to work, I think they'd have to make some way for inserters to put items from their hand *back* wherever they took them from. And then what happens if the thing they took them from is full now? It'd be very hairy.

[almania]

That solution also requires the trains to arrive completely empty, for trains to only ever leave due to "full inventory", and for _every_ train being serviced to conform to this to ensure they never pause midswing. Oh, and the target contents to be evenly divided by stack size * inserters...

Basically, none of those are true in my case. It also does not actually bother me if a couple of stack inserters to be blocked, it's unlikely for them all to be and they're all pulling from the same chests anyway. The next train to arrive will clear them anyway.

In game, it just strikes me as an issue that a disabled inserter is unloading steel on to a train that is only capable of unloading iron/copper. That steel ends up backing up over many visits until eventually there's no slots free on the train. I can use filtered slots, but I try for circuit managed inventories in many places (eg mixed goods from refinery), and I've found them very fragile in 0.17.

I do agree though, for a fully robust solution you need the inserter to be able to put _back_ an item, but a blocked inserter to me is a reasonable "oh, I didn't consider that" catch. One unloading despite being disabled... not so much.

[almania]

I suppose I could compute the number of slots consumed by the train contents and never allow a train to become full, and use circuit managed dispatch conditions (to ensure a train never leaves when an inserter is midswing), but this would be very combinator-intense. It's also rather messy with multiple wagons, as you'd need to ensure not one becomes full.

I'm actually unsure if there's a reasonable solution that does not involve removing the trash as it's put on, dedicating a whole track-side inserter position (and somehow getting it back in to the other chests). It's so hacky, basically filtered slots are required (meaning trains can only ever carry one config...)

[Vegemeister]

What about an "AND inactivity" departure condition? That requires no circuits.

As for removing garbage, maybe you could use one color of wire to control the loading inserters, and have them all wired together with the other color in read hold mode? That signal could be sent to a stack filter extractor once loading was complete, and items would be pulled off the train to make room for the overshoot.

[almania]

It's quite convoluted, isn't it.

I mean, how do you compactly load T=140 with steel, and T=165 with half Iron and half Copper without mixing? Currently, I have a completely conventional 2x12-chest (6 blue belt) station loader stack filter inserters and it nearly works, except for the garbage disabled inserters unload.

I guess rejigging for 2x11 chest with 2x1 filter-inserter trash removers on black-list mode (stack filter inserters cannot work without a lot more circuits - they only take 1 slot) and feeding the trash back to the inputs can work, but I do not think it should be required for anyone trying to follow in my footsteps here, as it really doesn't follow the principle of least astonishment. It's one of those things the game makes so hard w/ circuits that you go "guess filter slots is the only practical solution", which I thought the game tries to steer away from.

Thank you for your points though. I will do this for now, as I can (regrettably) see this not being addressed.

[TreefrogGreaken]

I believe this is working as intended. Jogged my memory on this one and i found the bug report from way back when.

viewtopic.php?f=11&t=49170

viewtopic.php?f=3&t=50029

viewtopic.php?f=3&t=50079

They did for a short amount of time revert the behaviour but there was a rather large backlash against the change as it broke lots of setups.

[Twinsen]

I believe this is working as intended. Jogged my memory on this one and i found the bug report from way back when.

viewtopic.php?f=11&t=49170

viewtopic.php?f=3&t=50029

viewtopic.php?f=3&t=50079

They did for a short amount of time revert the behaviour but there was a rather large backlash against the change as it broke lots of setups.

^This.
Basically there's no perfect solution. Read the first link to see what people said about it.

[JasonC]

I just reported this again, will read the above links, but note that there's also an issue when the inserter is unpowered, not just disabled.

Also fwiw I don't care about changes that break setups, especially setups that rely on nonsensical behaviors like disabled inserters that still do things. The game is still in alpha, that's what happens. There's been plenty of game-changing tweaks. Besides, upgrading factories to match new game versions gives me something to do.