[MC-125135] cave_air is not cleared after world generation

The bug

cave_air is meant to be used during world generation only and should afterwards be replaced by normal air, however for most features this is not the case, leaving cave_air behind.

Linked issues

is duplicated by 15

MC-133549 Underground structures generate using non-air blocks Resolved

MC-133980 When a cave is created, it is filled with blocks that are not transparent air blocks Resolved

MC-135705 Fill Command not replacing correctly in specific instance Resolved

MC-136336 Air in Ravines/Caves not actually air Resolved

MC-144924 Air does not generate in caves Resolved

10 more links

relates to 1

MC-191026 Cave air behaving very strangly when fill command is used in northwest corner of chunk border at specific y values Open

Comments 17

Greg Milson 2018-05-16T02:07:30Z

Still an issue in 18w20a

Greg Milson 2018-06-04T08:53:26Z

Affects 18w22c

Greg Milson 2018-06-27T12:31:14Z

Affects 1.13-pre4

Greg Milson 2018-07-05T04:15:22Z

Affects 1.13-pre6

Greg Milson 2018-07-13T12:34:49Z

Affects 1.13-pre8

7 more comments

Greg Milson 2020-10-23T15:45:37Z

Why is this won't fix? this issue breaks a lot of commands and a simple fix would be to add an #air block tag

Dmitry Konev 2020-10-24T11:26:02Z

This is actually useful. It's a very easy way to define caves from everything else. Of all things this shouldn't be considered a bug in the first place.

tryashtar 2020-10-25T23:39:35Z

Checking for cave air to determine whether an area is underground isn't very reliable, since it turns back to regular air whenever a block is mined

muzikbike 2021-10-11T00:14:36Z

Should this be reopened given changes to cave generation in 1.17 and 1.18?

Cratthorax 2021-12-23T06:33:34Z

I also don't see the valid reasoning behind this. I would use it in world generation only anyways. It's an easy way to check against air, that is not part of the surface. Now that its gone, I have to apply various new checks in its place, which unnecessarily bloats code.