[MC-88371] Ender Dragon flies down in the void when the exit portal is destroyed

The bug

If the exit portal is removed and the ender dragon tries to perch, it will fly to y=0. Doesn't matter if it's a hole or not, it will go through blocks tho.

How to reproduce

Enter the end.

/execute in minecraft:the_end run tp @s 0 100 0

Remove the exit portal (make sure the enderdragon is alive).
```
Stand on top of the exit portal and run: 
/fill ~-10 ~ ~10 ~10 ~-60 ~-10 air
```
→ ❌ The ender dragon flies to y=0, if it wants to perch.

Code analysis

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

Linked issues

relates to 2

MC-88301 Ender Dragon Breath freezes server when under or above the world Resolved

MC-90423 Ender Dragon makes breath attack at highest block placed in the center column of the portal Resolved

Attachments

MC-88371.mp4

Comments 32

Dominic staines 2015-09-10T16:09:37Z

The blue shield is a glitch it did not get removed from my inventory
i am in the affected version
just in case you dont know

[Mod] redstonehelper 2015-09-10T16:10:02Z

You can't break bedrock in survival, the dragon fight is geared towards survival.

PancakeMan77 2015-09-10T20:35:34Z

It is still a glitch. While the fight is meant for survival, this still happens and should be fixed

[Mod] redstonehelper 2015-09-10T20:36:58Z

Alright, reopened for Mojang to look at.

kumasasa 2015-09-11T06:29:29Z

There is a ticket where the ender dragon flies high up when the exit portal is extended on top, but cannot find it.

22 more comments

[Mod]Les3awe 2015-10-19T12:33:22Z

Confirmed for 15w42a

[Mod]Les3awe 2015-10-22T10:18:03Z

Confirmed for 15w43a

[Mod]Les3awe 2015-10-29T11:56:32Z

Confirmed for 15w44a

[Mod]Les3awe 2015-11-12T15:07:14Z

Confirmed for 15w46a

user-f2760 2016-03-13T16:36:11Z

The enviroment is supposed to contain pc details

[Mod]Les3awe 2016-04-10T16:23:36Z

Confirmed for 16w14a

[Mod]Les3awe 2016-05-03T13:58:10Z

Confirmed for 1.9.3-pre3

[Mod]Les3awe 2018-01-12T23:55:40Z

Confirmed for 18w02a.

[media]

Avoma 2020-12-13T16:50:32Z

Can confirm in 20w49a.

Avoma 2021-01-11T13:18:20Z

Can confirm in 20w51a.

Avoma 2021-01-24T11:42:46Z

Can confirm in 21w03a. If you don't want to wait for the ender dragon to fly down, feel free to use the following command:

/data merge entity @e[type=minecraft:ender_dragon,limit=1] {DragonPhase:3}

Avoma 2021-02-06T17:12:28Z

Can confirm in 21w05b.

Avoma 2021-02-12T16:16:58Z

Can confirm in 21w06a.

Chandler 2021-02-13T00:06:48Z

This is due to the end portal feature at net.minecraft.world.gen.feature.EndPortalFeature (yarn mappings 21w05b) defaulting its position to the origin (0,0,0) if no portal is found. The ender dragon landing phase reads from this to find its position.

public class EndPortalFeature extends Feature<DefaultFeatureConfig> {
    public static final BlockPos ORIGIN = BlockPos.ORIGIN;
    ...
}

From the dragon's landing phase:

public void serverTick() {
        if (this.target == null) {
            this.target = Vec3d.ofBottomCenter(this.dragon.world.getTopPosition(Heightmap.Type.MOTION_BLOCKING_NO_LEAVES, EndPortalFeature.ORIGIN));
        }
        ...
}

Avoma 2021-02-19T15:32:35Z

Can confirm in 21w07a.

Marty McFly 2021-03-24T12:40:10Z

Affects 21w11a

[Minecraft]Tony 2021-03-24T13:06:13Z

Can someone add a code to let the mobs go to different place ,to protect the players who saw the ender dragon fly into void.

like{ /mob -ender dragon -X-Y-Z to world(ender)

[Minecraft]Tony 2021-03-24T13:07:14Z

May the portal gets unbreakable?

Marty McFly 2021-05-27T14:11:42Z

Affects 1.17 Pre-release 1

Marty McFly 2021-06-08T15:37:00Z

Affects 1.17

Avoma 2021-10-03T11:32:35Z

I'd like to request ownership of this ticket since the current reporter has been inactive for over a year. I'm willing to keep this ticket updated and will continue to provide all of the necessary details.

Avoma 2022-03-20T12:28:57Z

Can confirm in 1.18.2.

Marty McFly 2022-04-01T21:02:50Z

Affects 22w13a

SeaOfPixels 2022-04-06T20:31:11Z

Relates to MC-201937, is a remnant of the ender dragon AI being broken in 19w08b effecting its decending behavior and its dragon phases.

ampolive 2022-04-18T21:55:52Z

@unknown This issue predates 19w08b, so it is very unlikely that they are related.

Avoma 2022-07-04T14:36:09Z

Can confirm in 1.19.

Dominic staines 2023-03-29T17:22:11Z

Hi, I reported this issue about 7 years ago when I was 10. You can see my account at the bottom of the history. I get emails every time it's updated! I don't even play minecraft anymore. Just wanted to say good job to all of the contributors that work on this game STILL to this day. Its amazing.