Remove all unnecessary calls to QSettings.sync().

This function is called automatically when a QSettings object is destroyed,
so is rarely needed to be called explicitly.

There are still some cases where
a QSettings object is passed-by-reference, so there I left the sync() calls as
it's unclear how permanent those objects are and if they'd call sync() before
application shutdown

src/GAudioOutput.cc

@@ -88,7 +88,6 @@ GAudioOutput::GAudioOutput(QObject *parent) : QObject(parent),
 {
     // Load settings
     QSettings settings;
-    settings.sync();
     muted = settings.value(QGC_GAUDIOOUTPUT_KEY + "muted", muted).toBool();
 
 
@@ -157,7 +156,6 @@ void GAudioOutput::mute(bool mute)
         this->muted = mute;
         QSettings settings;
         settings.setValue(QGC_GAUDIOOUTPUT_KEY + "muted", this->muted);
-        settings.sync();
         emit mutedChanged(muted);
     }
 }

src/QGCApplication.cc

@@ -132,7 +132,6 @@ QGCApplication::QGCApplication(int &argc, char* argv[], bool unitTesting) :
         // User requested settings to be cleared on command line
         settings.clear();
         settings.setValue(_settingsVersionKey, QGC_SETTINGS_VERSION);
-        settings.sync();
     }
     
 }

src/comm/MAVLinkProtocol.cc

@@ -90,7 +90,6 @@ void MAVLinkProtocol::loadSettings()
 {
     // Load defaults from settings
     QSettings settings;
-    settings.sync();
     settings.beginGroup("QGC_MAVLINK_PROTOCOL");
     enableHeartbeats(settings.value("HEARTBEATS_ENABLED", m_heartbeatsEnabled).toBool());
     enableVersionCheck(settings.value("VERSION_CHECK_ENABLED", m_enable_version_check).toBool());
@@ -133,8 +132,6 @@ void MAVLinkProtocol::storeSettings()
     settings.setValue("PARAMETER_REWRITE_TIMEOUT", m_paramRewriteTimeout);
     settings.setValue("PARAMETER_TRANSMISSION_GUARD_ENABLED", m_paramGuardEnabled);
     settings.endGroup();
-    settings.sync();
-    //qDebug() << "Storing settings!";
 }
 
 MAVLinkProtocol::~MAVLinkProtocol()

src/comm/QGCXPlaneLink.cc

@@ -92,7 +92,6 @@ void QGCXPlaneLink::loadSettings()
 {
     // Load defaults from settings
     QSettings settings;
-    settings.sync();
     settings.beginGroup("QGC_XPLANE_LINK");
     setRemoteHost(settings.value("REMOTE_HOST", QString("%1:%2").arg(remoteHost.toString()).arg(remotePort)).toString());
     setVersion(settings.value("XPLANE_VERSION", 10).toInt());
@@ -111,7 +110,6 @@ void QGCXPlaneLink::storeSettings()
     settings.setValue("AIRFRAME", airframeName);
     settings.setValue("SENSOR_HIL", _sensorHilEnabled);
     settings.endGroup();
-    settings.sync();
 }
 
 void QGCXPlaneLink::setVersion(const QString& version)

src/comm/SerialLink.cc

@@ -136,7 +136,6 @@ void SerialLink::loadSettings()
 {
     // Load defaults from settings
     QSettings settings;
-    settings.sync();
     if (settings.contains("SERIALLINK_COMM_PORT"))
     {
         m_portName = settings.value("SERIALLINK_COMM_PORT").toString();
@@ -160,7 +159,6 @@ void SerialLink::writeSettings()
     settings.setValue("SERIALLINK_COMM_STOPBITS", getStopBits());
     settings.setValue("SERIALLINK_COMM_DATABITS", getDataBits());
     settings.setValue("SERIALLINK_COMM_FLOW_CONTROL", getFlowType());
-    settings.sync();
 }
 
 void SerialLink::checkIfCDC()

src/input/JoystickInput.cc

@@ -69,7 +69,6 @@ void JoystickInput::loadGeneralSettings()
 {
     // Load defaults from settings
     QSettings settings;
-    settings.sync();
 
     // Deal with settings specific to the JoystickInput
     settings.beginGroup("JOYSTICK_INPUT");
@@ -86,7 +85,6 @@ void JoystickInput::loadJoystickSettings()
 {
     // Load defaults from settings
     QSettings settings;
-    settings.sync();
 
     // Now for the current joystick
     settings.beginGroup(joystickName);
@@ -162,7 +160,6 @@ void JoystickInput::storeGeneralSettings() const
     settings.setValue("ENABLED", isEnabled);
     settings.setValue("JOYSTICK_NAME", joystickName);
     settings.endGroup();
-    settings.sync();
 }
 
 void JoystickInput::storeJoystickSettings() const
@@ -254,7 +251,6 @@ void JoystickInput::storeJoystickSettings() const
     }
     settings.endArray(); // AUTOPILOTS
     settings.endGroup();
-    settings.sync();
 }
 
 void JoystickInput::setActiveUAS(UASInterface* uas)

src/uas/UAS.cc

@@ -271,7 +271,6 @@ void UAS::writeSettings()
     settings.setValue("AP_TYPE", this->autopilot);
     settings.setValue("BATTERY_SPECS", getBatterySpecs());
     settings.endGroup();
-    settings.sync();
 }
 
 /**

src/uas/UASManager.cc

@@ -63,13 +63,11 @@ void UASManager::storeSettings()
     settings.setValue("HOMELON", homeLon);
     settings.setValue("HOMEALT", homeAlt);
     settings.endGroup();
-    settings.sync();
 }
 
 void UASManager::loadSettings()
 {
     QSettings settings;
-    settings.sync();
     settings.beginGroup("QGC_UASMANAGER");
     bool changed =  setHomePosition(settings.value("HOMELAT", homeLat).toDouble(),
                                     settings.value("HOMELON", homeLon).toDouble(),

src/ui/DebugConsole.cc

@@ -138,7 +138,6 @@ void DebugConsole::loadSettings()
 {
     // Load defaults from settings
     QSettings settings;
-    settings.sync();
     settings.beginGroup("QGC_DEBUG_CONSOLE");
     m_ui->specialComboBox->setCurrentIndex(settings.value("SPECIAL_SYMBOL", m_ui->specialComboBox->currentIndex()).toInt());
     m_ui->specialCheckBox->setChecked(settings.value("SPECIAL_SYMBOL_CHECKBOX_STATE", m_ui->specialCheckBox->isChecked()).toBool());
@@ -159,7 +158,6 @@ void DebugConsole::storeSettings()
     settings.setValue("MAVLINK_FILTER_ENABLED", filterMAVLINK);
     settings.setValue("AUTO_HOLD_ENABLED", autoHold);
     settings.endGroup();
-    settings.sync();
 }
 
 void DebugConsole::uasCreated(UASInterface* uas)

src/ui/HDDisplay.cc

@@ -233,13 +233,11 @@ void HDDisplay::saveState()
     // qDebug() << "Saving" << instruments;
 
     settings.setValue(windowTitle()+"_gauges", instruments);
-    settings.sync();
 }
 
 void HDDisplay::restoreState()
 {
     QSettings settings;
-    settings.sync();
 
     acceptList->clear();
 

src/ui/MAVLinkSettingsWidget.cc

@@ -170,7 +170,6 @@ void MAVLinkSettingsWidget::enableDroneOS(bool enable)
         protocol->setAuthKey(m_ui->droneOSLineEdit->text().trimmed());
         QSettings settings;
         settings.setValue("DRONEOS_HOST", m_ui->droneOSComboBox->currentText());
-        settings.sync();
     }
     protocol->enableAuth(enable);
 }

src/ui/MainWindow.cc

@@ -179,7 +179,6 @@ MainWindow::MainWindow(QSplashScreen* splashScreen, enum MainWindow::CUSTOM_MODE
         }
     }
 
-    settings.sync();
     emit initStatusChanged(tr("Setting up user interface"), Qt::AlignLeft | Qt::AlignBottom, QColor(62, 93, 141));
 
     // Setup user interface
@@ -938,7 +937,6 @@ void MainWindow::loadCustomWidgetsFromDefaults(const QString& systemType, const
 void MainWindow::loadSettings()
 {
     QSettings settings;
-    settings.sync();
 
     customMode = static_cast<enum MainWindow::CUSTOM_MODE>(settings.value("QGC_CUSTOM_MODE", (unsigned int)MainWindow::CUSTOM_MODE_NONE).toInt());
 
@@ -977,7 +975,6 @@ void MainWindow::storeSettings()
 
     // And save any custom weidgets
     QGCToolWidget::storeWidgetsToSettings(settings);
-    settings.sync();
 }
 
 void MainWindow::configureWindowName()
@@ -1042,7 +1039,6 @@ void MainWindow::enableDockWidgetTitleBars(bool enabled)
     settings.beginGroup("QGC_MAINWINDOW");
     settings.setValue("DOCK_WIDGET_TITLEBARS",enabled);
     settings.endGroup();
-    settings.sync();
 }
 
 void MainWindow::enableAutoReconnect(bool enabled)

src/ui/QGCHilConfiguration.cc

@@ -42,7 +42,6 @@ QGCHilConfiguration::~QGCHilConfiguration()
     settings.beginGroup("QGC_HILCONFIG");
     settings.setValue("SIMULATOR_INDEX", ui->simComboBox->currentIndex());
     settings.endGroup();
-    settings.sync();
     delete ui;
 }
 

src/ui/QGCRGBDView.cc

@@ -40,7 +40,6 @@ void QGCRGBDView::storeSettings()
     settings.setValue("STREAM_RGB_ON", rgbEnabled);
     settings.setValue("STREAM_DEPTH_ON", depthEnabled);
     settings.endGroup();
-    settings.sync();
 }
 
 void QGCRGBDView::loadSettings()

src/ui/QGCStatusBar.cc

@@ -70,7 +70,6 @@ void QGCStatusBar::storeSettings()
     settings.beginGroup("QGC_MAVLINKLOGPLAYER");
     settings.setValue("LAST_LOG_DIRECTORY", lastLogDirectory);
     settings.endGroup();
-    settings.sync();
 }
 
 QGCStatusBar::~QGCStatusBar()

src/ui/QGCToolBar.cc

@@ -809,7 +809,6 @@ void QGCToolBar::storeSettings()
     QSettings settings;
     settings.beginGroup("QGC_TOOLBAR");
     settings.endGroup();
-    settings.sync();
 }
 
 void QGCToolBar::clearStatusString()

src/ui/configuration/terminalconsole.cpp

@@ -267,7 +267,6 @@ void TerminalConsole::loadSettings()
 {
     // Load defaults from settings
     QSettings settings;
-    settings.sync();
     if (settings.contains("TERMINALCONSOLE_COMM_PORT"))
     {
         m_settings.name = settings.value("TERMINALCONSOLE_COMM_PORT").toString();
@@ -295,7 +294,6 @@ void TerminalConsole::writeSettings()
     settings.setValue("TERMINALCONSOLE_COMM_STOPBITS", m_settings.stopBits);
     settings.setValue("TERMINALCONSOLE_COMM_DATABITS", m_settings.dataBits);
     settings.setValue("TERMINALCONSOLE_COMM_FLOW_CONTROL", m_settings.flowControl);
-    settings.sync();
 }
 
 

src/ui/linechart/LinechartWidget.cc

@@ -185,13 +185,11 @@ void LinechartWidget::writeSettings()
     if (ui.showUnitsCheckBox) settings.setValue("SHOW_UNITS", ui.showUnitsCheckBox->isChecked());
     if (ui.shortNameCheckBox) settings.setValue("SHORT_NAMES", ui.shortNameCheckBox->isChecked());
     settings.endGroup();
-    settings.sync();
 }
 
 void LinechartWidget::readSettings()
 {
     QSettings settings;
-    settings.sync();
     settings.beginGroup("LINECHART");
     if (activePlot) {
         timeButton->setChecked(settings.value("ENFORCE_GROUNDTIME", timeButton->isChecked()).toBool());

src/ui/map/QGCMapWidget.cc

@@ -306,7 +306,6 @@ void QGCMapWidget::storeSettings()
     settings.setValue("TRAIL_TYPE", static_cast<int>(trailType));
     settings.setValue("TRAIL_INTERVAL", trailInterval);
     settings.endGroup();
-    settings.sync();
 }
 
 void QGCMapWidget::mouseDoubleClickEvent(QMouseEvent* event)

src/ui/uas/UASQuickView.cc

@@ -104,7 +104,6 @@ void UASQuickView::saveSettings()
     }
     settings.endArray();
     settings.setValue("UAS_QUICK_VIEW_COLUMNS",m_columnCount);
-    settings.sync();
 }
 void UASQuickView::loadSettings()
 {