Open tone-test output before transmission

client.go

@@ -56,12 +56,8 @@ func (b *Barnard) connect(reconnect bool) bool {
 		// --- Tone test mode: skip all OpenAL; generate 440 Hz tone
 		// --- and save incoming audio to a file.
 
-		// Start the tone generator goroutine.
+		// Open the output first. Starting transmission before this succeeds
-		b.toneTestStop = make(chan struct{})
+		// leaves an orphaned tone goroutine when the path is unusable.
-		go StartToneGenerator(b.Client, b.toneTestStop)
-		b.Tx = true
-
-		// Attach the audio file saver.
 		saver, err := NewAudioFileSaver(b.ToneTestOutput)
 		if err != nil {
 			b.exitWithError(err)
@@ -70,6 +66,10 @@ func (b *Barnard) connect(reconnect bool) bool {
 		b.toneTestSaver = saver
 		b.Client.Config.AttachAudio(saver)
 
+		b.toneTestStop = make(chan struct{})
+		go StartToneGenerator(b.Client, b.toneTestStop)
+		b.Tx = true
+
 		b.Connected = true
 		return true
 	}

fix.txt

@@ -115,7 +115,7 @@ Priority 1: transport, lifecycle, and correctness
     closure: signal stop, wait for run to finish/close stdin and Wait ffmpeg,
     then return its result. Do not close stdin concurrently from Stop.
 
-14. Tone-test startup leaks transmission on output-file error
+[x] 14. Tone-test startup leaks transmission on output-file error
     File: client.go
     connect starts StartToneGenerator and sets Tx before NewAudioFileSaver. If
     output file creation fails, the tone goroutine continues. Create the saver

tonetest_test.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	"path/filepath"
+	"testing"
+)
+
+// Regression: tone transmission was started before opening its output file,
+// so a creation error left audio transmission running without cleanup.
+func TestNewAudioFileSaverReportsUnavailableOutputPath(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "missing", "tone.pcm")
+	if saver, err := NewAudioFileSaver(path); err == nil || saver != nil {
+		t.Fatalf("got saver=%v err=%v", saver, err)
+	}
+}