MC-95437Inconsistent entity data overriding when using spawn eggs on spawners
The bug
The problem is that you are unable to tell from the NBT data whether the SpawnData entity is the same entity object also stored in the SpawnPotentials which would cause both to be overridden when using a spawn egg. In this case you would be as well unable to tell which of the SpawnPotentials entries get overridden in case there are mutliple entries with the same tags and values. If the SpawnData entity is not in the SpawnPotentials list then only the SpawnData entity gets modified.
| SpawnData spawned | SpawnPotentials set | Changed tag |
|---|---|---|
 |
 |
SpawnData and SpawnPotentials |
 |
|
SpawnData |
|
|
SpawnData and SpawnPotentials |
Key
- SpawnData spawned = Spawner spawned the entity provided in the SpawnData tag already
- SpawnPotentials set = SpawnPotentials tag was set by a command, else the game adds this tag
- Changed tag = The tag that is changed
- = Yes
- = No
- = Does not matter
Note
For all the different situations listed above it does not matter if the SpawnData tag is set
Possible reason
| SpawnData spawned | SpawnPotentials set | Possible reason |
|---|---|---|
|
|
Next SpawnPotentials entity object is set as SpawnData, so both contain the same entity object |
|
|
Changing the entity stored as SpawnData with the spawn egg |
|
|
Same entity object of SpawnData is used in SpawnPotentials |
Possible solution
One way to solve this would be to have a tag called SpawnIndex (Integer) with these values:
| Value | Situation |
|---|---|
| -1 | SpawnData entity is not listed in SpawnPotentials |
| 0 to ... | SpawnData entity is listed in SpawnPotentials, value is index of entry |
How to reproduce
| SpawnData spawned | SpawnPotentials set | Spawner command |
|---|---|---|
|
|
/setblock ~ ~1 ~ mob_spawner 0 replace {SpawnData:{id:"ArmorStand",CustomName:"SpawnData",CustomNameVisible:1b},SpawnPotentials:[{Entity:{id:"ArmorStand",CustomName:"SpawnPotentials",CustomNameVisible:1b}}]}
|
|
|
/setblock ~ ~1 ~ mob_spawner 0 replace {SpawnData:{id:"ArmorStand",CustomName:"SpawnData",CustomNameVisible:1b},SpawnPotentials:[{Entity:{id:"ArmorStand",CustomName:"SpawnPotentials",CustomNameVisible:1b}}],Delay:32767s}
|
|
|
/setblock ~ ~1 ~ mob_spawner 0 replace {SpawnData:{id:"ArmorStand",CustomName:"SpawnData",CustomNameVisible:1b},Delay:32767s}
|
- Use the respective spawner command
- Right click with a Sheep spawn egg
- Inspect the NBT data of the spawner, for example with the following command (while standing on top of the spawner)
/blockdata ~ ~-1 ~ {}
Created Issue:
Inconsistent entity data overriding when using spawn eggs on spawners
The bug
When trying to change the Entity inside a spawner with a spawn egg, only for two different situations the SpawnPotentials tag will change as well:
- The SpawnPotentials tag was missing in the command for the spawner and was defaulted by Minecraft
- The spawner spawned the Entity in the SpawnData tag. In this case only the currently (by the spawner) selected SpawnPotential gets overridden.
This behavior might make sense however a way for the player to determine which entry will be overridden would be useful.
The bug
When you use a spawn egg on a spawner you are unable to tell which tag will change based on the NBT data of the spawner:
SpawnData spawned SpawnPotentials set Changed tag SpawnPotentials SpawnData SpawnData and SpawnPotentials Key
- SpawnData spawned = Spawner spawned the entity provided in the SpawnData tag already
- SpawnPotentials set = SpawnPotentials tag was set by a command, else the game adds this tag
- Changed tag = The tag that is changed
Possible reason
SpawnData spawned SpawnPotentials set Possible reason Next SpawnPotentials entity object is set as SpawnData internally Changing the entity stored as SpawnData Same entity object of SpawnData is used in SpawnPotentials How to reproduce
SpawnData spawned SpawnPotentials set Spawner command /setblock ~ ~1 ~ mob_spawner 0 replace {SpawnData:{id:"ArmorStand",CustomName:"SpawnData",CustomNameVisible:1b},SpawnPotentials:[{Entity:{id:"ArmorStand",CustomName:"SpawnPotentials",CustomNameVisible:1b}}]}/setblock ~ ~1 ~ mob_spawner 0 replace {SpawnData:{id:"ArmorStand",CustomName:"SpawnData",CustomNameVisible:1b},SpawnPotentials:[{Entity:{id:"ArmorStand",CustomName:"SpawnPotentials",CustomNameVisible:1b}}],Delay:32767s}/setblock ~ ~1 ~ mob_spawner 0 replace {SpawnData:{id:"ArmorStand",CustomName:"SpawnData",CustomNameVisible:1b},Delay:32767s}
- Use the respective spawner command
- Right click with a Sheep spawn egg
- Inspect the NBT data of the spawner, for example with the following command (while standing on top of the spawner)
/blockdata ~ ~-1 ~ {}
Changed Description:
The bug
When trying to change the Entity inside a spawner with a spawn egg, only for two different situations the SpawnPotentials tag will change as well:
- The SpawnPotentials tag was missing in the command for the spawner and was defaulted by Minecraft
- The spawner spawned the Entity in the SpawnData tag. In this case only the currently (by the spawner) selected SpawnPotential gets overridden.
This behavior might make sense however a way for the player to determine which entry will be overridden would be useful.
The bug
When you use a spawn egg on a spawner you are unable to tell which tag will change based on the NBT data of the spawner:
SpawnData spawned SpawnPotentials set Changed tag SpawnPotentials SpawnData SpawnData and SpawnPotentials Key
- SpawnData spawned = Spawner spawned the entity provided in the SpawnData tag already
- SpawnPotentials set = SpawnPotentials tag was set by a command, else the game adds this tag
- Changed tag = The tag that is changed
Possible reason
SpawnData spawned SpawnPotentials set Possible reason Next SpawnPotentials entity object is set as SpawnData internally Changing the entity stored as SpawnData with the spawn egg Same entity object of SpawnData is used in SpawnPotentials How to reproduce
SpawnData spawned SpawnPotentials set Spawner command
- Use the respective spawner command
- Right click with a Sheep spawn egg
- Inspect the NBT data of the spawner, for example with the following command (while standing on top of the spawner)
/blockdata ~ ~-1 ~ {}
Added Labels: SpawnData SpawnPotentials mob-spawner spawn-egg spawneggs spawner
Changed Description:
The bug
When trying to change the Entity inside a spawner with a spawn egg, only for two different situations the SpawnPotentials tag will change as well:
- The SpawnPotentials tag was missing in the command for the spawner and was defaulted by Minecraft
- The spawner spawned the Entity in the SpawnData tag. In this case only the currently (by the spawner) selected SpawnPotential gets overridden.
This behavior might make sense however a way for the player to determine which entry will be overridden would be useful.
The bug
When you use a spawn egg on a spawner you are unable to tell which tag will change based on the NBT data of the spawner:
SpawnData spawned SpawnPotentials set Changed tag SpawnPotentials SpawnData SpawnData and SpawnPotentials Key
- SpawnData spawned = Spawner spawned the entity provided in the SpawnData tag already
- SpawnPotentials set = SpawnPotentials tag was set by a command, else the game adds this tag
- Changed tag = The tag that is changed
Possible reason
SpawnData spawned SpawnPotentials set Possible reason Next SpawnPotentials entity object is set as SpawnData internally Changing the entity stored as SpawnData with the spawn egg Same entity object of SpawnData is used in SpawnPotentials How to reproduce
SpawnData spawned SpawnPotentials set Spawner command
- Use the respective spawner command
- Right click with a Sheep spawn egg
- Inspect the NBT data of the spawner, for example with the following command (while standing on top of the spawner)
/blockdata ~ ~-1 ~ {}The bug
When you use a spawn egg on a spawner you are unable to tell which tag will change based on the NBT data of the spawner:
SpawnData spawned SpawnPotentials set Changed tag SpawnPotentials SpawnData SpawnData and SpawnPotentials Key
- SpawnData spawned = Spawner spawned the entity provided in the SpawnData tag already
- SpawnPotentials set = SpawnPotentials tag was set by a command, else the game adds this tag
- Changed tag = The tag that is changed
Possible reason
SpawnData spawned SpawnPotentials set Possible reason Next SpawnPotentials entity object is set as SpawnData internally Changing the entity stored as SpawnData with the spawn egg Same entity object of SpawnData is used in SpawnPotentials How to reproduce
SpawnData spawned SpawnPotentials set Spawner command
- Use the respective spawner command
- Right click with a Sheep spawn egg
- Inspect the NBT data of the spawner, for example with the following command (while standing on top of the spawner)
/blockdata ~ ~-1 ~ {}
Added Linked Issues:
relates to
Changed Description:
The bug
When you use a spawn egg on a spawner you are unable to tell which tag will change based on the NBT data of the spawner:
SpawnData spawned SpawnPotentials set Changed tag Spawn PotentialsSpawnData SpawnData and SpawnPotentials Key
- SpawnData spawned = Spawner spawned the entity provided in the SpawnData tag already
- SpawnPotentials set = SpawnPotentials tag was set by a command, else the game adds this tag
- Changed tag = The tag that is changed
Possible reason
SpawnData spawned SpawnPotentials set Possible reason Next SpawnPotentials entity object is set as SpawnData internally Changing the entity stored as SpawnData with the spawn egg Same entity object of SpawnData is used in SpawnPotentials How to reproduce
SpawnData spawned SpawnPotentials set Spawner command
- Use the respective spawner command
- Right click with a Sheep spawn egg
- Inspect the NBT data of the spawner, for example with the following command (while standing on top of the spawner)
/blockdata ~ ~-1 ~ {}The bug
When you use a spawn egg on a spawner you are unable to tell which tag will change based on the NBT data of the spawner:
SpawnData spawned SpawnPotentials set Changed tag SpawnData and SpawnPotentials SpawnData SpawnData and SpawnPotentials Key
- SpawnData spawned = Spawner spawned the entity provided in the SpawnData tag already
- SpawnPotentials set = SpawnPotentials tag was set by a command, else the game adds this tag
- Changed tag = The tag that is changed
Possible reason
SpawnData spawned SpawnPotentials set Possible reason Next SpawnPotentials entity object is set as SpawnData, so both contain the same entity object Changing the entity stored as SpawnData with the spawn egg Same entity object of SpawnData is used in SpawnPotentials How to reproduce
SpawnData spawned SpawnPotentials set Spawner command
- Use the respective spawner command
- Right click with a Sheep spawn egg
- Inspect the NBT data of the spawner, for example with the following command (while standing on top of the spawner)
/blockdata ~ ~-1 ~ {}
![[Bot] Arisa](../../../data/assets/gravatar/mustek2.png){kind=small}
![[Mod] redstonehelper](../../../data/avatars/users/10122.svg){kind=small}
Added Linked Issues:
is duplicated by
Changed Description:
The bug
When you use a spawn egg on a spawner you are unable to tell which tag will change based on the NBT data of the spawner:
SpawnData spawned SpawnPotentials set Changed tag SpawnData and SpawnPotentials SpawnData SpawnData and SpawnPotentials Key
- SpawnData spawned = Spawner spawned the entity provided in the SpawnData tag already
- SpawnPotentials set = SpawnPotentials tag was set by a command, else the game adds this tag
- Changed tag = The tag that is changed
Possible reason
SpawnData spawned SpawnPotentials set Possible reason Next SpawnPotentials entity object is set as SpawnData, so both contain the same entity object Changing the entity stored as SpawnData with the spawn egg Same entity object of SpawnData is used in SpawnPotentialsHow to reproduce
SpawnData spawned SpawnPotentials set Spawner command
- Use the respective spawner command
- Right click with a Sheep spawn egg
- Inspect the NBT data of the spawner, for example with the following command (while standing on top of the spawner)
/blockdata ~ ~-1 ~ {}The bug
When you use a spawn egg on a spawner you are unable to tell which tag will change based on the NBT data of the spawner:
SpawnData spawned SpawnPotentials set Changed tag SpawnData and SpawnPotentials SpawnData SpawnData and SpawnPotentials Key
- SpawnData spawned = Spawner spawned the entity provided in the SpawnData tag already
- SpawnPotentials set = SpawnPotentials tag was set by a command, else the game adds this tag
- Changed tag = The tag that is changed
Note
For all the different situations listed above it does not matter if the SpawnData tag is set
Possible reason
SpawnData spawned SpawnPotentials set Possible reason Next SpawnPotentials entity object is set as SpawnData, so both contain the same entity object Changing the entity stored as SpawnData with the spawn egg Same entity object of SpawnData is used in SpawnPotentials Possible solution
One way to solve this would be to have a tag called SpawnIndex (Integer) with these values:
Value Situation -1 SpawnData entity is not listed in SpawnPotentials 0 to ... SpawnData entity is listed in SpawnPotentials, value is index of entry How to reproduce
SpawnData spawned SpawnPotentials set Spawner command
- Use the respective spawner command
- Right click with a Sheep spawn egg
- Inspect the NBT data of the spawner, for example with the following command (while standing on top of the spawner)
/blockdata ~ ~-1 ~ {}
Changed Description:
The bug
When you use a spawn egg on a spawner you are unable to tell which tag will change based on the NBT data of the spawner:
SpawnData spawned SpawnPotentials set Changed tag SpawnData and SpawnPotentials SpawnData SpawnData and SpawnPotentials Key
- SpawnData spawned = Spawner spawned the entity provided in the SpawnData tag already
- SpawnPotentials set = SpawnPotentials tag was set by a command, else the game adds this tag
- Changed tag = The tag that is changed
Note
For all the different situations listed above it does not matter if the SpawnData tag is set
Possible reason
SpawnData spawned SpawnPotentials set Possible reason Next SpawnPotentials entity object is set as SpawnData, so both contain the same entity object Changing the entity stored as SpawnData with the spawn egg Same entity object of SpawnData is used in SpawnPotentials Possible solution
One way to solve this would be to have a tag called SpawnIndex (Integer) with these values:
Value Situation -1 SpawnData entity is not listed in SpawnPotentials 0 to ... SpawnData entity is listed in SpawnPotentials, value is index of entry How to reproduce
SpawnData spawned SpawnPotentials set Spawner command
- Use the respective spawner command
- Right click with a Sheep spawn egg
- Inspect the NBT data of the spawner, for example with the following command (while standing on top of the spawner)
/blockdata ~ ~-1 ~ {}The bug
The problem is that you are unable to tell from the NBT data whether the SpawnData entity is the same entity object also stored in the SpawnPotentials which would cause both to be overridden when using a spawn egg. In this case you would be as well unable to tell which of the SpawnPotentials entries get overridden in case there are mutliple entries with the same tags and values. If the SpawnData entity is not in the SpawnPotentials list then only the SpawnData entity gets modified.
SpawnData spawned SpawnPotentials set Changed tag SpawnData and SpawnPotentials SpawnData SpawnData and SpawnPotentials Key
- SpawnData spawned = Spawner spawned the entity provided in the SpawnData tag already
- SpawnPotentials set = SpawnPotentials tag was set by a command, else the game adds this tag
- Changed tag = The tag that is changed
Note
For all the different situations listed above it does not matter if the SpawnData tag is set
Possible reason
SpawnData spawned SpawnPotentials set Possible reason Next SpawnPotentials entity object is set as SpawnData, so both contain the same entity object Changing the entity stored as SpawnData with the spawn egg Same entity object of SpawnData is used in SpawnPotentials Possible solution
One way to solve this would be to have a tag called SpawnIndex (Integer) with these values:
Value Situation -1 SpawnData entity is not listed in SpawnPotentials 0 to ... SpawnData entity is listed in SpawnPotentials, value is index of entry How to reproduce
SpawnData spawned SpawnPotentials set Spawner command
- Use the respective spawner command
- Right click with a Sheep spawn egg
- Inspect the NBT data of the spawner, for example with the following command (while standing on top of the spawner)
/blockdata ~ ~-1 ~ {}
Added Affects Versions: 1.9-pre2
![[Mod] Neko](../../../data/avatars/users/92901.png){kind=small}
Added Linked Issues:
relates to
MC-111317
Added Affects Versions: 1.11.2
Removed Labels: spawneggs
Added Linked Issues:
is duplicated by
![[Mod] Michael Wobst](../../../data/avatars/users/37868.png){kind=small}
![[Mod] violine1101](../../../data/avatars/users/92858.png){kind=small}
Please provide some textual description of this issue. Based on your tables alone it is very hard to figure out the problem.
I am unclear what the expected/desired behavior ought to be, and what makes this a bug. This just sounds like a (somewhat interesting and possibly useful to mapmakers) specification of the existing behavior.
[Mod] redstonehelper, the bug is described in the first sentence but maybe a little bit too less in detail:
The problem is basically that you are unable to tell from the NBT data whether the SpawnData entity is the same entity object also stored in the SpawnPotentials which would cause both to be overridden. In this case you would be as well unable to tell which of the SpawnPotentials entries get overridden in case there are mutliple entries with the same tags and value. If the SpawnData entity is not in the SpawnPotentials list then only the SpawnData entity gets modified.
But the current behaviour is probably intended, you just need to know about it.
Confirmed for 1.9-pre2
Confirmed for 1.10-pre1.
Is this still an issue in the latest snapshot 16w44a? If so please update the affected versions.
This is an automated comment on any open or reopened issue with out-of-date affected versions.
Confirmed for 1.11.2
I am not sure I understand this ticket correctly, but the following bug can be reproduced easily on MC 1.12.1, both on a server and client world, and I assume it relates to this issue:
Expected result: The mob-spawner will now spawn zombies instead of pigs.
Actual result: The mob-spawner will spawn one (wave of) zombie(s), and then switch back to spawning pigs. Reason: After each spawn wave the mob-spawner checks its SpawnPotentials (if it isn't empty) for the next entity to spawn, and replaces the SpawnData with the picked entity. And this list only contains 'Pig' after the save-load-cycle and even after changing the SpawnData with the spawn_egg.
Possible fix: Maybe clear the internal SpawnPotentials of the mob-spawner after the mob type was changed via a spawn_egg.
And / Or: Don't include the SpawnsData in the SpawnPotentials when being saved and having an empty SpawnPotentials list. So the blockdata-command will report correct (the actual) data, and the data doesn't change after a save-load-cycle.
I am sure and I know what the bug is. They don't delete the spawn potentials and current spawndata they get mobspawner logic and change a string that's it. It doesn't work they need to create method to reset both spawndata and spawnpotentials when right click on egg. Whether it be from the eggs fix which it should have to be a couple lines edited or they choose to add a reset mob spawner mobs method it needs to get fixed. Either way the ItemMonsterPlacer.class needs edits
Is this still a issue in the latest version of the game(currently 1.13.1)?
If so, please add it to the affected versions, thanks!