The bug
I would imagine that this is not indented behavior, but this is definitely interesting for sure.
Basically, if there is a string on the surface of the water above a magma block, boats are immediately sunken when going over it instead of taking a few seconds to go down.
How to reproduce
Demonstrated here: https://youtu.be/0TAOiJovdtw
Linked issues
Attachments
Comments
@Donald Kerner
Yes, I know magma blocks are supposed to sink things (ex: players, boats, entities, etc), that is not the point of this report. The point is that if you have string on the surface above a magma block, it sinks boats immediately instead of eventually. I believe this not to be intended by the developers.
Ps: I am a developer (not at Mojang tho)
Confirmed for 1.13.2-pre2.

Affects 20w29a I would like to request ownership of this report
Can confirm in 21w05b.
Can confirm in 21w06a.
Can confirm in 1.17.1.
Can confirm in 1.19.2.

Can confirm in 1.21 with video evidence https://1drv.ms/v/s!Av8d-ZGdHED9yetQjj5kVMILImB5ew?e=1IRrtY
[media]
Well magma sinks things so even though I'm not a developer, Magma underwater sinks things not floats, that's soul sand.