[MC-3984] A re-created Hardcore game isn't Hardcore unless you cycle through game modes and reset it to Hardcore

The bug

A re-created Hardcore game isn't Hardcore (despite the 'Game Mode' button displaying 'Hardcore') unless you cycle through game modes and reset it to Hardcore.

How to reproduce

Select a hardcore game and then 'Re-Create'
Don't change the game mode settings
Select 'Create New World' button
→ ❌ Notice that a survival world has been created even though the 'Game Mode' button said 'Hardcore'

Code analysis

Code analysis by @unknown can be found in this comment.

Linked issues

is duplicated by 4

MC-1355 Reload Hardcore isn't so Hardcore Resolved

MC-8476 Cheats and bonus chest with hardcore mode. Resolved

MC-58290 re-create hardcore shows hardcore but creates survival Resolved

MC-156479 Re-creating a world! Resolved

relates to 1

MC-10209 'Allow Cheats' and 'Bonus Chest' buttons get unlocked after entering superflat/buffet customization options Resolved

Comments 17

Tails 2012-12-31T19:16:31Z

Confirmed in 1.4.7.

Buzzaro 2013-01-02T18:06:54Z

I didn't check if this same thing would happen with any of the other game modes.

Pedro M. Zamboni 2013-01-26T23:58:05Z

Confirmed in 13w04a

alef 2013-05-23T00:42:08Z

13w19a. The level.dat of re-created hardcore world has TAG_Byte(hardcore) set to 0, while the original is 1.

alef 2014-01-19T14:29:26Z

Confirmed in 14w03b

7 more comments

ggxl 2014-06-26T21:24:32Z

Does this default any other settings (such as if structures were turned off, the chest was turned on, etc.)?

marcono1234 2014-07-20T11:07:55Z

Confirmed for

14w29b
14w30c
14w31a
Minecraft 1.8-pre 1

Interesting question ggxl, but it seems like it only affects hardcore mode (tried with creative mode and re-create and worked fine) also with chests, it just seems like it sets it to false when pressing re-create, but when you check the settings before re-creating it also says that you have bonus chest set to false

marcono1234 2015-09-11T13:48:34Z

Confirmed for

15w37a

andrew h 2015-12-11T13:06:12Z

I think that "recreate" doesn't make the same world, it automatically fills in the seed. You can still change the options surrounding the world

SunCat 2015-12-11T21:11:26Z

It shoud set the same set up options as in the original world (such as world type, gamemode, bonus chest and so on)

Hayden Muhl 2016-03-05T02:32:32Z

Confirming for 1.9

marcono1234 2016-07-03T16:58:27Z

Please link to this comment in the description

The following is based on a decompiled version of Minecraft 1.10 using MCP 9.30.

This is happening because the method net.minecraft.client.gui.GuiCreateWorld.recreateFromExistingWorld(WorldInfo) is not setting the boolean field net.minecraft.client.gui.GuiCreateWorld.hardCoreMode to true. This should be fixed by removing this field completely and determining if a gamemode is hardcore by the net.minecraft.client.gui.GuiCreateWorld.gameMode field only. In case there will be game modes other than "hardcore", which have the same hardcore mechanism however, the gamemodes could be enum values that overrite the method toString() to return the String version and have a method that returns whether or not a mode is hardcore.

bemoty 2016-08-16T17:33:27Z

Still happens in 16w32b.

bemoty 2017-01-02T16:37:52Z

Confirmed for 1.11.2

bemoty 2017-08-09T14:14:22Z

Can confirm for MC 1.12.1.

Kraif 2018-08-29T16:02:37Z

Confirmed for 1.13.1. Please, if you don't mind, I'd like to be the reporter of this issue, I'll update it accordingly.

Derek Smith 2018-10-14T14:33:10Z

It would be nice if Mojang fixed (ancient) bugs like this instead of adding new content to the game. Mods can already add more content to the game than Mojang can dream of, but they can't fix bugs, so Mojang is ultimately just wasting time. ¬_¬