[0.17.69] Pipes do not exhibit flow animations when placed directly before eastern-facing pumps

[Kirbykirby56]

I've got a pretty interesting one for you here. When a pump is pumping eastward (->), it will show the pipe before it as having no flow (e.g. the animation is stopped, but the underlying values seem perfectly fine.

Recreation:
(Check Video 2 to watch me recreate this from startup)
Step 1: Obtain any fluid source (Oil, water, etc.)
Step 2: Place a right-facing pump somewhere it's powered
Step 3: Connect the input of the pump to somewhere, and the output of the pump to somewhere. A good way to do this is to fill the pipes a bit with something, disconnect the input, and then close the pipe ring so that the flow is continuous.
The pipe's animations before the engine will be stagnant.

Expectation:
The pipe would have the flow animation like all the other pipes in the chain

Reality:
The pipe has a stagnant animation
(This seems to happen every time.)

Interestingly enough, as seen in my video 2, it seems to only happen on rightward facing pumps.

And here's the links again but defined in terms of video number:
Video 1 (Me finding it during play): https://youtu.be/n1lXl8PHG2A
Video 2 (Me experimenting in Sandbox): https://youtu.be/ft1c-YtEtRk (Video 2 is now available)

[Honktown]

Sorry, I saw this and wanted to see because I like pumps. Terrible reason I know.

The flow is actually different facing east/west, not just the animation. I made a square of pipe filled with water, and the west facing pump stabilizes with a value of under 100 on both sides, but the east-facing pump doesn't, and it jitters with 100 water to the east.

This bug also affects north/south, slightly differently. The north facing pump stabilizes with less than 100 on both sides. A south facing pump's flow stabilizes, with 100 in front of it, and a non-moving window behind.

When a dev finds the bug, I'd like to know what it was. I used to work as a debugger and this is neat-o.

[MasterBuilder]

I believe this is caused by the update order of pipes. West wins and takes all the fluid it can. Then east updates and there's nothing (or almost nothing) to go east.
IIRC pipes do not currently split fluids evenly. This is something that should fixed at some point in the future when the new fluid algorithm is merged in.

Now, I could be completely wrong here as it's in "Assigned" and not just bug reports. I also don't remember what parts, if any, were merged in from the new fluid algorithm, so...

[Dominik]

Yeah the new algo will fix that for sure. But if one day, after lunch, I feel like I have nothing to do, I might fix it as well

[Canis]

Also, the first pipe connected to a storage tank also doesn't show correct flow when more than one pipe is connected in sequence, in some directions.

[movax20h]

Also, the first pipe connected to a storage tank also doesn't show correct flow when more than one pipe is connected in sequence, in some directions.

I can't reproduce the issue with storage tanks in 0.17.79. Could you post a screenshot or blueprint?

I can reproduce the original issue with first pipe element before (left) of the pump not animating, like in the first comment tho.

[Canis]

Here you go. Running 0.17.79 with no mods.