fix errors when switching to Game state and add fast_login test

3 files changed, 52 insertions, 7 deletions

diff --git a/azalea-client/src/plugins/packet/config/events.rs b/azalea-client/src/plugins/packet/config/events.rs
index a9b2179a..eddcf72f 100644
--- a/azalea-client/src/plugins/packet/config/events.rs
+++ b/azalea-client/src/plugins/packet/config/events.rs
@@ -55,7 +55,7 @@ pub fn handle_send_packet_event(
     }
 }
 
-pub fn send_packet_events(
+pub fn emit_receive_config_packet_events(
     query: Query<(Entity, &RawConnection), With<InConfigState>>,
     mut packet_events: ResMut<Events<ReceiveConfigPacketEvent>>,
 ) {
@@ -67,7 +67,9 @@ pub fn send_packet_events(
         let packets_lock = raw_conn.incoming_packet_queue();
         let mut packets = packets_lock.lock();
         if !packets.is_empty() {
+            let mut packets_read = 0;
             for raw_packet in packets.iter() {
+                packets_read += 1;
                 let packet = match deserialize_packet::<ClientboundConfigPacket>(&mut Cursor::new(
                     raw_packet,
                 )) {
@@ -78,13 +80,32 @@ pub fn send_packet_events(
                         continue;
                     }
                 };
+
+                let should_interrupt = packet_interrupts(&packet);
+
                 packet_events.send(ReceiveConfigPacketEvent {
                     entity: player_entity,
                     packet,
                 });
+
+                if should_interrupt {
+                    break;
+                }
             }
-            // clear the packets right after we read them
-            packets.clear();
+            packets.drain(0..packets_read);
         }
     }
 }
+
+/// Whether the given packet should make us stop deserializing the received
+/// packets until next update.
+///
+/// This is used for packets that can switch the client state.
+fn packet_interrupts(packet: &ClientboundConfigPacket) -> bool {
+    matches!(
+        packet,
+        ClientboundConfigPacket::FinishConfiguration(_)
+            | ClientboundConfigPacket::Disconnect(_)
+            | ClientboundConfigPacket::Transfer(_)
+    )
+}
diff --git a/azalea-client/src/plugins/packet/game/events.rs b/azalea-client/src/plugins/packet/game/events.rs
index 9e7f88fa..e5c87971 100644
--- a/azalea-client/src/plugins/packet/game/events.rs
+++ b/azalea-client/src/plugins/packet/game/events.rs
@@ -75,7 +75,7 @@ pub fn handle_outgoing_packets(
     }
 }
 
-pub fn send_receivepacketevent(
+pub fn emit_receive_packet_events(
     query: Query<(Entity, &RawConnection), With<InGameState>>,
     mut packet_events: ResMut<Events<ReceivePacketEvent>>,
 ) {
@@ -87,7 +87,9 @@ pub fn send_receivepacketevent(
         let packets_lock = raw_connection.incoming_packet_queue();
         let mut packets = packets_lock.lock();
         if !packets.is_empty() {
+            let mut packets_read = 0;
             for raw_packet in packets.iter() {
+                packets_read += 1;
                 let packet =
                     match deserialize_packet::<ClientboundGamePacket>(&mut Cursor::new(raw_packet))
                     {
@@ -98,17 +100,36 @@ pub fn send_receivepacketevent(
                             continue;
                         }
                     };
+
+                let should_interrupt = packet_interrupts(&packet);
+
                 packet_events.send(ReceivePacketEvent {
                     entity: player_entity,
                     packet: Arc::new(packet),
                 });
+
+                if should_interrupt {
+                    break;
+                }
             }
-            // clear the packets right after we read them
-            packets.clear();
+            packets.drain(0..packets_read);
         }
     }
 }
 
+/// Whether the given packet should make us stop deserializing the received
+/// packets until next update.
+///
+/// This is used for packets that can switch the client state.
+fn packet_interrupts(packet: &ClientboundGamePacket) -> bool {
+    matches!(
+        packet,
+        ClientboundGamePacket::StartConfiguration(_)
+            | ClientboundGamePacket::Disconnect(_)
+            | ClientboundGamePacket::Transfer(_)
+    )
+}
+
 /// A player joined the game (or more specifically, was added to the tab
 /// list of a local player).
 #[derive(Event, Debug, Clone)]
diff --git a/azalea-client/src/plugins/packet/mod.rs b/azalea-client/src/plugins/packet/mod.rs
index cbd8a175..96a396d9 100644
--- a/azalea-client/src/plugins/packet/mod.rs
+++ b/azalea-client/src/plugins/packet/mod.rs
@@ -38,7 +38,10 @@ impl Plugin for PacketPlugin {
     fn build(&self, app: &mut App) {
         app.add_systems(
             First,
-            (game::send_receivepacketevent, config::send_packet_events),
+            (
+                game::emit_receive_packet_events,
+                config::emit_receive_config_packet_events,
+            ),
         )
         .add_systems(
             PreUpdate,