fixes is_interior(), fixing xeno construction on dropships during transport

[harryob]

huh? how'd this not get reported?

🆑
fix: xenos can construct in dropships during transport again
/:cl:

[SabreML]

Wow, that was fast.

[Drulikar]

Can confirm changes work on a hijacked dropship in tranit:

[Doubleumc]

If this does what I think it does (reserved-but-not-interior turfs don't inherently count as interior) you can revert part of #4815 https://github.com/cmss13-devs/cmss13/pull/4815/files#diff-150200d3d67a0db8d052db8dfcfa37b39396e514b3bef9d708dcce5d7e1bdd7aL45-R45

[Drulikar]

If this does what I think it does (reserved-but-not-interior turfs don't inherently count as interior) you can revert part of #4815 https://github.com/cmss13-devs/cmss13/pull/4815/files#diff-150200d3d67a0db8d052db8dfcfa37b39396e514b3bef9d708dcce5d7e1bdd7aL45-R45

I don't think there's currently any change there. if . was assigned it would matter; but the default return value should already be 0 aka FALSE; though maybe its actually null - either case it should be falsey - just not sure what it returns for isnull.

[Doubleumc]

I don't think there's currently any change there. if . was assigned it would matter; but the default return value should already be 0 aka FALSE; though maybe its actually null - either case it should be falsey - just not sure what it returns for isnull.

It makes a difference because the return (VI) is subjected to a null check, which 0/FALSE would pass.

cmss13/code/game/sound.dm

Lines 82 to 84 in 98f032b

	if(SSinterior.in_interior(turf_source))
	var/datum/interior/VI = SSinterior.get_interior_by_coords(turf_source.x, turf_source.y, turf_source.z)
	if(VI?.ready)

Also described here: #4815 (comment)

If reserved-but-not-interior turfs counting as interior is undesired, reverting this change would cause exceptions to be thrown if one managed to be created again.