Fix loss of constellation when device restarted in M17 demod.

plugins/channelrx/demodm17/m17demod.cpp

@@ -57,7 +57,8 @@ M17Demod::M17Demod(DeviceAPI *deviceAPI) :
         m_thread(nullptr),
         m_basebandSink(nullptr),
         m_running(false),
-        m_basebandSampleRate(0)
+        m_basebandSampleRate(0),
+        m_scopeXYSink(nullptr)
 {
     qDebug("M17Demod::M17Demod");
 	setObjectName(m_channelId);
@@ -141,6 +142,7 @@ void M17Demod::start()
     if (m_basebandSampleRate != 0) {
         m_basebandSink->setBasebandSampleRate(m_basebandSampleRate);
     }
+    m_basebandSink->setScopeXYSink(m_scopeXYSink);
 
     m_basebandSink->reset();
     m_thread->start();
@@ -751,3 +753,11 @@ void M17Demod::handleIndexInDeviceSetChanged(int index)
     m_basebandSink->setFifoLabel(fifoLabel);
     m_basebandSink->setAudioFifoLabel(fifoLabel);
 }
+
+void M17Demod::setScopeXYSink(BasebandSampleSink* sampleSink)
+{
+    m_scopeXYSink = sampleSink;
+    if (m_running) {
+        m_basebandSink->setScopeXYSink(sampleSink);
+    }
+}

plugins/channelrx/demodm17/m17demod.h

@@ -209,7 +209,7 @@ public:
             SWGSDRangel::SWGChannelSettings& response);
 
     uint32_t getNumberOfDeviceStreams() const;
-	void setScopeXYSink(BasebandSampleSink* sampleSink) { if (m_running) { m_basebandSink->setScopeXYSink(sampleSink); } }
+	void setScopeXYSink(BasebandSampleSink* sampleSink);
 	void configureMyPosition(float myLatitude, float myLongitude) { if (m_running) { m_basebandSink->configureMyPosition(myLatitude, myLongitude); } }
 	double getMagSq() { return m_running ? m_basebandSink->getMagSq() : 0.0; }
 	bool getSquelchOpen() const { return m_running && m_basebandSink->getSquelchOpen(); }
@@ -281,7 +281,7 @@ private:
     bool m_running;
 	M17DemodSettings m_settings;
     int m_basebandSampleRate; //!< stored from device message used when starting baseband sink
-
+    BasebandSampleSink *m_scopeXYSink;
     QNetworkAccessManager *m_networkManager;
     QNetworkRequest m_networkRequest;