2 files changed, 80 insertions, 0 deletions
diff --git a/internal/net/server.go b/internal/net/server.go
index b0407fc..42077a1 100644
--- a/internal/net/server.go
+++ b/internal/net/server.go
@@ -174,7 +174,15 @@ func (sess *Session) StartWriter() {
 // enqueue appends msg to the outbound queue. When the client's queue is full
 // the session is disconnected instead of blocking the caller: the world must
 // never wait on a single slow client.
+// enqueue appends msg to the outbound queue. When the client's queue is
+// full the session is disconnected instead of blocking the caller: the world
+// must never wait on a single slow client.
 func (sess *Session) enqueue(msg string) {
+	// A broadcast can race Close(): the queue may already be (or become)
+	// closed mid-send. Such late writes are dropped, never panicked on —
+	// Close() closes the queue so the writer goroutine drains whatever was
+	// queued before the close and then flushes the transport.
+	defer func() { _ = recover() }()
 	select {
 	case sess.outbox <- msg:
 	default:
@@ -490,6 +498,10 @@ func (s *Server) serveTelnet() {
 			Conn:  newTCPConn(conn),
 			State: StateAccountName,
 		}
+		// Queued writes like the websocket transport: a dedicated writer
+		// goroutine performs the I/O with per-message deadlines, so a slow
+		// or stalled telnet client can never block game code.
+		sess.StartWriter()
 		s.hub.Add(sess)
 		go s.handleSession(sess, s.handler)
 	}
@@ -505,6 +517,7 @@ func (s *Server) serveTelnetTLS() {
 			Conn:  newTCPConn(conn),
 			State: StateAccountName,
 		}
+		sess.StartWriter()
 		s.hub.Add(sess)
 		go s.handleSession(sess, s.handler)
 	}
diff --git a/internal/net/session_writer_test.go b/internal/net/session_writer_test.go
new file mode 100644
index 0000000..94de4ba
--- /dev/null
+++ b/internal/net/session_writer_test.go
@@ -0,0 +1,67 @@
+package net
+
+import (
+	stdnet "net"
+	"testing"
+	"time"
+
+	"thehouseoficarus/internal/config"
+)
+
+// TestEnqueueAfterCloseDoesNotPanic: a broadcast racing Close() must drop
+// the message, never panic on a send to the closed outbound queue.
+func TestEnqueueAfterCloseDoesNotPanic(t *testing.T) {
+	conn := &testConn{}
+	sess := &Session{Conn: conn}
+	sess.StartWriter()
+	sess.Close()
+
+	defer func() {
+		if r := recover(); r != nil {
+			t.Fatalf("write after Close panicked: %v", r)
+		}
+		// Wait for the writer goroutine to drain and exit cleanly.
+		select {
+		case <-sess.writeDone:
+		case <-time.After(time.Second):
+			t.Fatal("writer goroutine never exited after close")
+		}
+	}()
+	for i := 0; i < 3; i++ {
+		sess.WriteLine("late broadcast")
+	}
+}
+
+// TestTelnetSessionUsesQueuedWriter: production telnet sessions must start
+// the queued writer like the websocket transport, so slow clients get
+// per-message write deadlines and can never block game code.
+func TestTelnetSessionUsesQueuedWriter(t *testing.T) {
+	cfg := config.Default()
+	cfg.Telnet.Enabled = true
+	cfg.Telnet.Port = 0
+	s, err := NewServer(cfg)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer s.Shutdown()
+
+	observed := make(chan bool, 1)
+	s.handler = func(sess *Session, _ string) { observed <- sess.outbox != nil }
+	go s.serveTelnet()
+
+	conn, err := stdnet.Dial("tcp", s.telnetLn.Addr().String())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+	conn.Write([]byte("hello\n"))
+
+	select {
+	case queued := <-observed:
+		if !queued {
+			t.Fatal("telnet session has no outbound queue; writes are synchronous and can stall the world")
+		}
+	case <-time.After(time.Second):
+		t.Fatal("session handler was not invoked")
+	}
+}