feat: add command auto-completion when running behind a proxy (#16)

Author: Quozul

README.md

@@ -23,7 +23,7 @@ packets required for client login and maintaining connection (keep-alive) withou
 When idle, PicoLimbo uses almost no resources: 0% CPU and less than 10 MB of memory, making it extremely lightweight.
 
 While not aiming to replicate every Minecraft server feature, PicoLimbo supports **all Minecraft versions from 1.7.2
-through 1.21.6**, excluding snapshots, with only 27 implemented packets covering over 46 different protocol versions or
+through 1.21.6**, excluding snapshots, with only 28 implemented packets covering over 46 different protocol versions or
 74 Minecraft versions.
 
 ## Features

binaries/pico_limbo/src/handlers/configuration.rs

@@ -7,6 +7,7 @@ use minecraft_packets::configuration::registry_data_packet::{
     RegistryDataCodecPacket, RegistryDataPacket,
 };
 use minecraft_packets::play::chunk_data_and_update_light_packet::ChunkDataAndUpdateLightPacket;
+use minecraft_packets::play::commands_packet::CommandsPacket;
 use minecraft_packets::play::game_event_packet::GameEventPacket;
 use minecraft_packets::play::legacy_chat_message_packet::LegacyChatMessage;
 use minecraft_packets::play::login_packet::LoginPacket;
@@ -102,6 +103,11 @@ pub async fn send_play_packets(client: Client, state: ServerState) -> Result<(),
         client.send_packet(packet).await?;
     }
 
+    if protocol_version >= ProtocolVersion::V1_13 {
+        let packet = CommandsPacket::empty();
+        client.send_packet(packet).await?;
+    }
+
     if protocol_version >= ProtocolVersion::V1_20_3 {
         // Send Game Event
         let packet = GameEventPacket::start_waiting_for_chunks(0.0);

crates/minecraft_packets/src/play/commands_packet.rs

@@ -0,0 +1,50 @@
+use minecraft_protocol::prelude::*;
+use thiserror::Error;
+
+/// This packet is sent since 1.13
+#[derive(Debug, PacketOut)]
+#[packet_id("play/clientbound/minecraft:commands")]
+pub struct CommandsPacket {
+    /// An array of nodes.
+    nodes: LengthPaddedVec<Node>,
+    /// Index of the `root` node in the previous array.
+    root_index: VarInt,
+}
+
+impl CommandsPacket {
+    pub fn empty() -> Self {
+        Self {
+            nodes: vec![Node {
+                flags: 0,
+                children: LengthPaddedVec::default(),
+            }]
+            .into(),
+            root_index: VarInt::from(0),
+        }
+    }
+}
+
+#[derive(Debug, Default)]
+struct Node {
+    flags: i8,
+    /// Array of indices of child nodes.
+    children: LengthPaddedVec<VarInt>,
+}
+
+#[derive(Debug, Error)]
+pub enum NodeError {
+    #[error(transparent)]
+    LengthPaddedVecEncode(#[from] LengthPaddedVecEncodeError),
+    #[error(transparent)]
+    Infallible(#[from] std::convert::Infallible),
+}
+
+impl EncodePacketField for Node {
+    type Error = NodeError;
+
+    fn encode(&self, bytes: &mut Vec<u8>, protocol_version: u32) -> Result<(), Self::Error> {
+        self.flags.encode(bytes, protocol_version)?;
+        self.children.encode(bytes, protocol_version)?;
+        Ok(())
+    }
+}

crates/minecraft_packets/src/play/mod.rs

@@ -1,5 +1,6 @@
 pub mod chunk_data_and_update_light_packet;
 pub mod client_bound_keep_alive_packet;
+pub mod commands_packet;
 mod data;
 pub mod game_event_packet;
 pub mod legacy_chat_message_packet;

data/generated/V1_13/reports/packets.json

@@ -46,6 +46,9 @@
       },
       "minecraft:legacy_chat_message": {
         "protocol_id": 14
+      },
+      "minecraft:commands": {
+        "protocol_id": 17
       }
     },
     "serverbound": {}

data/generated/V1_14/reports/packets.json

@@ -46,6 +46,9 @@
       },
       "minecraft:legacy_chat_message": {
         "protocol_id": 14
+      },
+      "minecraft:commands": {
+        "protocol_id": 17
       }
     },
     "serverbound": {}

data/generated/V1_15/reports/packets.json

@@ -46,6 +46,9 @@
       },
       "minecraft:legacy_chat_message": {
         "protocol_id": 15
+      },
+      "minecraft:commands": {
+        "protocol_id": 18
       }
     },
     "serverbound": {}

data/generated/V1_16/reports/packets.json

@@ -46,6 +46,9 @@
       },
       "minecraft:legacy_chat_message": {
         "protocol_id": 14
+      },
+      "minecraft:commands": {
+        "protocol_id": 17
       }
     },
     "serverbound": {}

data/generated/V1_16_2/reports/packets.json

@@ -52,6 +52,9 @@
       },
       "minecraft:legacy_chat_message": {
         "protocol_id": 14
+      },
+      "minecraft:commands": {
+        "protocol_id": 16
       }
     },
     "serverbound": {}

data/generated/V1_17/reports/packets.json

@@ -52,6 +52,9 @@
       },
       "minecraft:legacy_chat_message": {
         "protocol_id": 15
+      },
+      "minecraft:commands": {
+        "protocol_id": 18
       }
     },
     "serverbound": {}