Allow sneak toggling when player does not have the fly privilege

[y5nw]

Fixes #16780 by implementing the alternative solution.

This only affects the situation where fly mode is enabled but the player does not have the fly privilege. Sneak toggling remains disabled if the player has fly privilege and enables fly mode.

This PR is Ready for Review.

How to test

• Revoke fly mode of the player.
• Enable fly mode.
• Enable sneak toggling.
• Enable sneaking.
• Oberserve that the player is sneaking.
• Grant fly mode to the player.
• Observe that the player is no longer sneaking.

[Xeno333]

Flight can exist without fly priv. And the setting doesn't correspond to the priv.

[y5nw]

Flight can exist without fly priv.

I am not aware of this. Do you have an example where free_move can be used by a player without the fly privilege?

Flight-related behavior that is specific to mods (e.g. controlling aircrafts) is IMO out of scope for consideration here as the same could also be said about other mods that use the sneak key for other purposes than sneaking.

And the setting doesn't correspond to the priv.

Elaborate?

[Xeno333]

Most common is modded clients

[y5nw]

Most common is modded clients

How are modded clients relevant here? For what reason would the authors of such clients be unable to revert this change themselves?

[SmallJoker]

Couldn't we simply set free_move = false if the player lacks such privilege? Or would that be game-breaking where mods/games only briefly revoke privileges (e.g. within one or two server steps)?

EDIT: I am asking because this kind of check does exist in multiple places, and it seems error-prone when it's necessary to always check both at once.

[y5nw]

EDIT: I am asking because this kind of check does exist in multiple places, and it seems error-prone when it's necessary to always check both at once.

Alternatively one can write a helper function to check whether flying is enabled by the client and allowed by the server, but IMO that belongs to a different PR.

[4Arcturus]

I just tested this, and seems to work as intended. I will close my issue tomorrow.

[y5nw]

I will close my issue tomorrow.

You do not need to do that manually.

• This PR is not merged yet.
• The linked issue will be automatically closed when this PR is merged.

[4Arcturus]

I see.