Make Internet test optional.

src/QGCApplication.cc

@@ -741,7 +741,9 @@ void QGCApplication::qmlAttemptWindowClose()
 
 bool QGCApplication::isInternetAvailable()
 {
-    return getQGCMapEngine()->isInternetActive();
+    if(_toolbox->settingsManager()->appSettings()->checkInternet()->rawValue().toBool())
+        return getQGCMapEngine()->isInternetActive();
+    return true;
 }
 
 void QGCApplication::_checkForNewVersion()

src/QtLocationPlugin/QGCMapEngine.cpp

@@ -543,7 +543,10 @@ QGCCreateTileSetTask::~QGCCreateTileSetTask()
 void
 QGCMapEngine::testInternet()
 {
-    getQGCMapEngine()->addTask(new QGCTestInternetTask());
+    if(qgcApp()->toolbox()->settingsManager()->appSettings()->checkInternet()->rawValue().toBool())
+        getQGCMapEngine()->addTask(new QGCTestInternetTask());
+    else
+        _internetStatus(true);
 }
 
 //-----------------------------------------------------------------------------

src/QtLocationPlugin/QGeoTileFetcherQGC.cpp

@@ -79,7 +79,7 @@ QGeoTileFetcherQGC::getTileImage(const QGeoTileSpec &spec)
         return new QGeoTiledMapReplyQGC(_networkManager, request, spec);
     }
     else {
-        return NULL;
+        return nullptr;
     }
 }
 

src/Settings/App.SettingsGroup.json

@@ -96,6 +96,13 @@
     "type":             "bool",
     "defaultValue":     false
 },
+{
+    "name":             "checkInternet",
+    "shortDescription": "Check Internet connection",
+    "longDescription":  "Check Internet connection before accessing Internet resources.",
+    "type":             "bool",
+    "defaultValue":     true
+},
 {
     "name":             "virtualJoystick",
     "shortDescription": "Show virtual joystick",

src/Settings/AppSettings.cc

@@ -77,6 +77,7 @@ DECLARE_SETTINGSFACT(AppSettings, defaultMissionItemAltitude)
 DECLARE_SETTINGSFACT(AppSettings, telemetrySave)
 DECLARE_SETTINGSFACT(AppSettings, telemetrySaveNotArmed)
 DECLARE_SETTINGSFACT(AppSettings, audioMuted)
+DECLARE_SETTINGSFACT(AppSettings, checkInternet)
 DECLARE_SETTINGSFACT(AppSettings, virtualJoystick)
 DECLARE_SETTINGSFACT(AppSettings, virtualJoystickCentralized)
 DECLARE_SETTINGSFACT(AppSettings, appFontPointSize)

src/Settings/AppSettings.h

@@ -32,6 +32,7 @@ public:
     DEFINE_SETTINGFACT(telemetrySave)
     DEFINE_SETTINGFACT(telemetrySaveNotArmed)
     DEFINE_SETTINGFACT(audioMuted)
+    DEFINE_SETTINGFACT(checkInternet)
     DEFINE_SETTINGFACT(virtualJoystick)
     DEFINE_SETTINGFACT(virtualJoystickCentralized)
     DEFINE_SETTINGFACT(appFontPointSize)

src/ui/preferences/GeneralSettings.qml

@@ -255,6 +255,13 @@ Rectangle {
                                     property Fact _audioMuted: QGroundControl.settingsManager.appSettings.audioMuted
                                 }
 
+                                FactCheckBox {
+                                    text:       qsTr("Check for Internet connection")
+                                    fact:       _checkInternet
+                                    visible:    _checkInternet.visible
+                                    property Fact _checkInternet: QGroundControl.settingsManager.appSettings.checkInternet
+                                }
+
                                 FactCheckBox {
                                     text:       qsTr("AutoLoad Missions")
                                     fact:       _autoLoad