output/Thread: move code to InternalCloseOutput()

src/output/Control.hxx

@@ -429,6 +429,12 @@ private:
 	void InternalOpen(AudioFormat audio_format,
 			  const MusicPipe &pipe) noexcept;
 
+	/**
+	 * Runs inside the OutputThread.
+	 * Caller must lock the mutex.
+	 */
+	void InternalCloseOutput(bool drain) noexcept;
+
 	/**
 	 * Runs inside the OutputThread.
 	 * Caller must lock the mutex.

src/output/Thread.cxx

@@ -60,14 +60,10 @@ AudioOutputControl::InternalOpen2(const AudioFormat in_audio_format)
 
 	const auto cf = in_audio_format.WithMask(output->config_audio_format);
 
-	if (open && cf != output->filter_audio_format) {
+	if (open && cf != output->filter_audio_format)
 		/* if the filter's output format changes, the output
 		   must be reopened as well */
-		open = false;
+		InternalCloseOutput(true);
-
-		const ScopeUnlock unlock(mutex);
-		output->CloseOutput(true);
-	}
 
 	output->filter_audio_format = cf;
 
@@ -175,6 +171,17 @@ AudioOutputControl::InternalOpen(const AudioFormat in_audio_format,
 			    ToString(output->out_audio_format).c_str());
 }
 
+inline void
+AudioOutputControl::InternalCloseOutput(bool drain) noexcept
+{
+	assert(IsOpen());
+
+	open = false;
+
+	const ScopeUnlock unlock(mutex);
+	output->CloseOutput(drain);
+}
+
 inline void
 AudioOutputControl::InternalClose(bool drain) noexcept
 {