FOSS gamedev and creative worlds

How do I rename a player in Minetest?

Or should I just log in as a different name, and have the old player give all his stuff to the new one? But what about locked chests and things like that?

In your "worlds/myworld/players" folder, just rename the singleplayer file to the name of your new player; this should transfer the singleplayer inventory and position to your new user (or do a copy).

For locked chests, ... There is a mod in the forum providing a "tool" that allows you to change an item's owner (punch the chest and it becomes yours). But I can not find it back.

viewtopic.php?f=9&t=13358

This will allow you to change locked chest ownership.