Repository navigation
fix(players): decode signed actor IDs in the player list - #458
Merged
RaphiMC merged 1 commit intoOct 19, 2026
Conversation
PlayerListAddEntry uses compressed ActorUniqueID, a signed 64-bit value in the Bedrock 1.26.51 protocol-2193 schema. Decode its ZigZag representation consistently with StartGame instead of retaining the unsigned wire value. The private protocol-2193 skin relay exposed the mismatch: a spawned actor with ID 1 appeared in PlayerListStorage under ID 2. Live skin changes could not resolve the local UUID, and scoreboard associations could resolve another actor. Gophertunnel emits signed IDs as specified by the native schema. Evidence: https://github.com/Mojang/bedrock-protocol-docs/blob/v1.26.51/json/PlayerListAddEntry.json and https://github.com/Mojang/bedrock-protocol-docs/blob/v1.26.51/json/ActorUniqueID.json
Exterminate5573
approved these changes
Oct 19, 2026
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
What this changes
PlayerListAddEntry uses compressed ActorUniqueID, a signed 64-bit value in the Bedrock 1.26.51 protocol-2193 schema. Decode its ZigZag representation consistently with StartGame instead of retaining the unsigned wire value.
The private protocol-2193 skin relay exposed the mismatch: a spawned actor with ID 1 appeared in PlayerListStorage under ID 2. Live skin changes could not resolve the local UUID, and scoreboard associations could resolve another actor. Gophertunnel emits signed IDs as specified by the native schema.
Evidence: https://github.com/Mojang/bedrock-protocol-docs/blob/v1.26.51/json/PlayerListAddEntry.json and https://github.com/Mojang/bedrock-protocol-docs/blob/v1.26.51/json/ActorUniqueID.json
This PR contains one patch from StackAnvil's viabedrock stack, applied alone to the pinned upstream base.
Review focus
Replace the unsigned decoder with the existing signed VarLong decoder.
The change affects only the player-list actor ID field.
For example, actor ID 1 previously decoded as 2, so later actor lookups could fail or select another actor.
The protocol 2193 schemas define a compressed signed 64-bit actor ID:
Validation
bun run pr build viabedrock --patch 0060-decode-signed-player-list-actor-ids.patchpasses, including compilation and Checkstyle.The patch applies alone to the pinned upstream base and changes one production line.
The existing skin-relay observation is recorded in the commit body; this preparation did not repeat a live server capture.