/gamemode also changes the default game mode, as if changed by /defaultgamemode

Due to the changes made recently, gamemode and defaultgamemode have become extremely inconsistent, inconvenient and incomprehensible. I am going to explain all the different scenarios that cause unexpected behavior in a series of tickets after I lay down the expected behavior. These were all covered in a single ticket by another user, which was resolved because it was invalid due to multiple bugs in one ticket.

Terminology

• World visibility state

  • Singleplayer: A world that is created through singleplayer world creation, is NOT open to LAN only housing a single player.

  • Open to LAN: A world that is created through singleplayer world creation, but is opened to LAN. It houses 1 or more players.

  • Multiplayer: A world that is created through dedicated server multiplayer world creation. It houses 0 or more players.

• Gamemode state

  • (Player) Gamemode: The gamemode of an individual player.

  • Default Gamemode: the default gamemode of the world which is traditionally modified with /defaultgamemode and shows up on the level select screen in singleplayer. (or in server.properties > gamemode=<GAMEMODE> for servers)

  • LAN Gamemode: the temporary default gamemode which applies only in Open to LAN worlds to other players.

  • Forced Gamemode: the gamemode to switch players to upon joining. Found in server.properties force-gamemode=<bool>

Expected

• if I deliberately force the defaultgamemode to be survival, and I change to creative mode, I do NOT expect the defaultgamemode to change, I want to have control, and being explicit and deliberate about changing it, should not make gamemode changes in the future change this. it would be very confusing.

  • Take for example, I want to make a fix to an existing world download, I quickly pop into creative to make my fixes and close the world and reupload it. Now it messes up the defaultgamemode, despite me having deliberately set it to survival prior to changing gamemode.

Actual

• In singleplayer, if I deliberately force the defaultgamemode to be survival, and I change to creative mode, the defaultgamemode changes. (Not as expected)

Please check the attached video. It explains many of the issues found in the post I am copying from (but not all), as it visually shows many of these scenarios. https://www.youtube.com/watch?v=kUegubINAiw