dialog action commands longer than the chat limit disconnects the player

[superstorm192]

Expected behavior

You run the command and it sets the player head texture to the texture you want

Observed/Actual behavior

You are kicked from the server with error:

lost connection: Internal Exception: io.netty.handler.codec.DecoderException: Failed to decode packet 'serverbound/minecraft:chat_command'

Steps/models to reproduce

dialog show @p {"type":"minecraft:multi_action","title":
        {"text":"Set Texture"},"inputs":[
            {"type":"minecraft:text","key":"value","max_length":200,"label":{"text":"Text"}}
        ],"actions":[
          {"label":{"text":"Apply Texture"},"action":{"type":"minecraft:dynamic/run_command",
            "template":"item modify entity @s weapon.mainhand {function:\"minecraft:set_components\",components:{\"minecraft:profile\":{properties:[{\"name\":\"textures\",\"value\":\"$(value)\"}]}}}"
          }}
        ],"exit_action":{"label":{"text":"Cancel"}}}

1. copy the code above into a command block
2. put a blank player head in your main hand
3. trigger the command block
4. enter this in the box: eyJ0ZXh0dXJlcyI6eyJTS0lOIjp7InVybCI6Imh0dHA6Ly90ZXh0dXJlcy5taW5lY3JhZnQubmV0L3RleHR1cmUvNzIyODYzMjRiNmIwNmMyZDRjMWQ4ZjgzYTliMTQwZDdjYWJkODI4MWRiOTcyYjI0M2QyZTYyZDFhMjNkMDA1NCJ9fX0=
5. press the Apply Texture button
6. observe that you are kicked from the server.

Next thing to try:

• try steps 1-5 on a vanilla minecraft server with no paper installed
• observe that it works and sets your player head with no error

Plugin and Datapack List

None

Paper version

paper-26.2-117

Other

The following code can be ran to show that below the limit, the dialogs do indeed run correctly in Paper normally.

dialog show @p {"type":"minecraft:multi_action","title":
        {"text":"Set Custom Name"},"inputs":[
            {"type":"minecraft:text","key":"value","max_length":500,"label":{"text":"Text"}}
        ],"actions":[
          {"label":{"text":"Apply Name"},"action":{"type":"minecraft:dynamic/run_command",
            "template":"item modify entity @s weapon.mainhand {function:\"minecraft:set_components\",components:{\"minecraft:custom_name\":{\"text\":\"$(value)\"}}}"
          }}
        ],"exit_action":{"label":{"text":"Cancel"}}}

I suspect that the dialog may be sending packets that are counted as invalid when they are valid on a vanilla minecraft server.

[masmc05]

It's kind of expected, if I remember correctly there's no distinction to the server between a chat executed command and command executed by clicking, if there were then there would be mods that would just make all comand executions as click event executions, resulting in potential crashes.
The only solution for your case is using custom clicks and handling them with a plugin
And are you sure you ran this on a server and not singleplayer? Nvm the issue is that in vanilla it's validated only client side, on paper it's also validated server side for crash preventions, configurable with -Dpaper.maxChatCommandInputSize

[superstorm192]

It's kind of expected, if I remember correctly there's no distinction to the server between a chat executed command and command executed by clicking, if there were then there would be mods that would just make all comand executions as click event executions, resulting in potential crashes. The only solution for your case is using custom clicks and handling them with a plugin And are you sure you ran this on a server and not singleplayer? Nvm the issue is that in vanilla it's validated only client side, on paper it's also validated server side for crash preventions, configurable with -Dpaper.maxChatCommandInputSize

Yeah, I tested it on a brand new empty server just in case and on that server it worked just fine, added paper, kicked. The -Dpaper.maxChatCommandInputSize might help, thanks. I hope there's a way to get dialogs to work like that, but if i can't for other servers, i could just for mine.