[Kovarex] [2.0.33] Smart Belt Dragging completes underground section but removes existing surface belt

[travvo]

I had a belt that meandered between two lanes because of placement of regular splitters (on a spaceship originally, space constrained). I went to add a second belt in the lower row, using the smart belt drag, and while it successfully put an underground section to build the lower belt, it removed one of the tiles of the pre-existing surface belt. I would expect this tile wouldn't be removed:

20250205133241_1.jpg (908.72 KiB) Viewed 1061 times

By contrast, the belt dragging on the right was all accomplished without removing surface belts.

Log:

factorio-current.log

(12.91 KiB) Downloaded 33 times

Save (new start with /editor):

Belt_Test.zip

(1.31 MiB) Downloaded 28 times

[kovarex]

This is more of a feature request than a bug report, because I was never sure how to approach the splitter and belt dragging to not make more harm than good.
But I tried a simple approach of this: (from the changelog)

- Extended belt traversing logic to also traverse splitter as long as the last built belt before the splitter didn't exist already before the dragging.

[travvo]

Thank you, Kovarex! I appreciate you!