Fix crash in issue 3845 and defects B/C in 3779

src/client.cpp

@@ -738,6 +738,8 @@ void CClient::SetAudioChannels ( const EAudChanConf eNAudChanConf )
 
 QString CClient::SetSndCrdDev ( const QString strNewDev )
 {
+    QString strError = "";
+
     // if client was running then first
     // stop it and restart again after new initialization
     const bool bWasRunning = Sound.IsRunning();
@@ -746,16 +748,23 @@ QString CClient::SetSndCrdDev ( const QString strNewDev )
         Sound.Stop();
     }
 
-    const QString strError = Sound.SetDev ( strNewDev );
+    try
+    {
+        strError = Sound.SetDev ( strNewDev );
 
-    // init again because the sound card actual buffer size might
-    // be changed on new device
-    Init();
+        // init again because the sound card actual buffer size might
+        // be changed on new device
+        Init();
 
-    if ( bWasRunning )
+        if ( bWasRunning )
+        {
+            // restart client
+            Sound.Start();
+        }
+    }
+    catch ( const CGenErr& generr )
     {
-        // restart client
-        Sound.Start();
+        strError = generr.GetErrorText();
     }
 
     // in case of an error inform the GUI about it
@@ -853,7 +862,8 @@ void CClient::OnSndCrdReinitRequest ( int iSndCrdResetType )
 
     // audio device notifications can come at any time and they are in a
     // different thread, therefore we need a mutex here
-    MutexDriverReinit.lock();
+    QMutexLocker locker ( &MutexDriverReinit );
+    try
     {
         // in older QT versions, enums cannot easily be used in signals without
         // registering them -> workaroud: we use the int type and cast to the enum
@@ -888,7 +898,10 @@ void CClient::OnSndCrdReinitRequest ( int iSndCrdResetType )
             Sound.Start();
         }
     }
-    MutexDriverReinit.unlock();
+    catch ( const CGenErr& generr )
+    {
+        strError = generr.GetErrorText();
+    }
 
     // inform GUI about the sound card device change
     emit SoundDeviceChanged ( strError );

src/clientdlg.cpp

@@ -866,7 +866,7 @@ void CClientDlg::OnCLVersionAndOSReceived ( CHostAddress InetAddr, COSUtil::EOpS
         {
             // show the label and hide it after one minute again
             lblUpdateCheck->show();
-            QTimer::singleShot ( 60000, [this]() { lblUpdateCheck->hide(); } );
+            QTimer::singleShot ( 60000, this, [this]() { lblUpdateCheck->hide(); } );
         }
 #endif
     }