Filed / Tracking Pasting with selection tools doesn't properly update the FEA model for SI [00684]

Mode: Creative
Mode: SP

SERVER NAME: NA
SEED-ID: NA

MODIFIED PLAYFIELDS: No

Reproducibility: Always
Severity: Possibly major if a BP collapses when spawned normally when it didn't while being created.

Type: SI

Summary: When pasting a selection that contains empty blocks over some existing blocks, the blocks are removed as they should be (because they were empty in the selected copy) but the FEA model for SI still "thinks" they are there.

Description: When pasting a selection results in removal of blocks, the SI model is not updated with the removal. As a result, anything on top of those empty blocks shows no stress the same as it would if blocks were present.

Steps to Reproduce:

1. Enter creative mode, place a base starter, and create a hollow box of say 20x20x5 blocks.
2. Select the whole box with the selection tool EXCEPT for one of the walls of the box.
3. Paste the selection and move it over 20 blocks in one direction so that one of the walls of the box will be removed when it is pasted.
4. Turn on SI debug and notice that the area where the wall used to be is green, as though the wall were still there, which it should not be.
5. Observe that the wall isn't there.
6. Manually place some blocks where the wall was and manually remove them (using Shift Right click for example). notice the SI model is updated properly when you do this.

Screenshots attached.



Another screenshot:



It should end up like this and collapse in the center like this:



This BP might be useful to help test:

https://steamcommunity.com/sharedfiles/filedetails/?id=1645416908

Add some supports in the middle, add roof, then remove the supports by pasting a selection over them.

 

Ok, sorry for the bad example. That's more of a real use case example but it's less clear than a contrived example.

Here's a simplified contrived example that shows the problem. (I didn't have any good video recording software installed, though I guess I could have used ShareX for that, but anyway I think this is step-by-step enough to show the problem.)

Create this shape in creative mode:



Now select 1x1x2 (same shape as the pillar) and copy empty space:



Paste the empty space over the pillar:



This happens:





So I'm left with the top part floating.

But if I add blocks manually again:




Then remove one with shift-right-click:



Then it collapses just like it should.

let me know if you still need me to make a video