[0.18.32] Fluid mixing by quick-replace

[warlordship]

Long story short, it appears you can now quick-replace Underground pipes with regular pipes. This allows fluid mixing in situations where the quick-replace should have been blocked.

Mods Installed:
Construction Drones (I built these pipes manually. Possible having this mod installed can mess with fluid mixing mechanics?)
Power Armor Mk3
Vehicle Grid
Water Well (pump free water from the ground)

What I was doing: I was manually building my favorite oil cracking setup. As seen below, it is 3 parallel rows of fluids, with space in between enough for a chemical plant. I line up the plant with the refinery above so that the I/O pipes for the plants don't conflict with the refinery. What I intended to do was what is seen here:


I thought I was safe to move along at a decent pace. move some steps, click, move, click. My timing must have been off, and I clicked too early, which you can see here:


I EXPECTED the fluid mixing mechanics to prevent this replace. This pipe will be connected to both gas AND light oil, which is bad. As seen here, the pipe is now filled with Petroleum gas. The pipe below the selected is visibly filled with light oil:


I am at that point unable to place the pipe in the correct spot, because the new pipe to the left is the wrong fluid. This is correct and normal:


Interestingly, this seems to cause more issues further along. My first time, I hadn't noticed the mis-click, and moved on to the next chemical plant. I was very confused when I was told I could not connect the pipe between two light oil sources, as seen here:


It seems to turn the entire light oil line into a strange state, and not allow any more light oil sources to connect up. It appears to turn the entire light-oil line AND gas line into a dual-liquid line. This can now only mix with another dual-liquid line of the same kind. Meaning I cannot hook up a new "clean" light-oil line or a "clean" gas line. I am able to make a 5x5 (or bigger) grid of pipes that randomly picks between the two fluids, which further tells me that the entire pipe is now dual-fluid and accepts any other pipe of that kind, no matter which fluid actually occupies the pipe next to it. This - in essence - destroys the fluid mixing prevention mechanic for that pipe until the sources are cut off and the wrong fluid flushed.

Interestingly (again), the new fluid flush mechanic even shows that it knows it is a dual fluid system:

[Rseding91]

Thanks for the report. That's known and won't be changed. Just remove the wrong connection, flush the wrong fluid, and go back to business as usual.

[warlordship]

Ooookay..... But are you sure this is intended(ish) behavior? I don't recall having the ability to quick replace an UG pipe with a regular and have fluid mixing come up before now. This seems like a disturbingly easy way to get around the fluid mixing prevention mechanic, one that can easily happen without even knowing.

Did you use to be able to quick-replace UG pipes with regular before? If so, did it prevent fluid mixing?

Because, as it is, I seem to be hampered by the fluid-mix-prevention mechanic when it doesn't matter, and not protected by it when I needed it. There's another bug I came across that I am trying to figure out that caused an empty pipe connected up to a machine with no recipe that reserved the empty pipe for the wrong fluid.

[invisus]

You are aware of the fluid-mixing simplifications as presented in FFF-351, yes?

Fluid Mixing Prevention
"Just try to handle the most common case - manually building things - and in the more complex cases where mixing might happen, provide a quick-and-easy way to fix it: a button to flush all of a given fluid from the pipes."

They're specifically stating that they're going to remove a heap of the fluid mixing prevention "bumpers" and instead, just present the ability to flush the pipes.

So there are likely to be a LOT of cases like this, that are no longer prevented by the game, but that this behavior is now more or less intentional, as you now have a reasonable (less punishing) method to address it. i.e. fix the problem, flush the pipes