Launcher bugfix: custom download dirs

Partial fixes for:
https://sourceforge.net/p/flightgear/codetickets/2019/

But further work needed on Windows I expect, will do that now.

src/GUI/LauncherController.cxx

@@ -344,9 +344,9 @@ void LauncherController::downloadDirChanged(QString path)
         return;
     }
 
-    // if the default dir is passed in, map that back to the emptru string
+    // if the default dir is passed in, map that back to the empty string
     if (path == m_config->defaultDownloadDir()) {
-        path.clear();;
+        path.clear();
     }
 
     auto options = flightgear::Options::sharedInstance();
@@ -364,25 +364,9 @@ void LauncherController::downloadDirChanged(QString path)
         options->clearOption("download-dir");
     }
 
-    // replace existing package root
+    m_config->setValueForKey("", "download-dir", path);
-    globals->get_subsystem<FGHTTPClient>()->shutdown();
+    saveSettings();
-    globals->setPackageRoot(simgear::pkg::RootRef());
+    flightgear::restartTheApp();
-
-    // create new root with updated download-dir value
-    fgInitPackageRoot();
-
-    globals->get_subsystem<FGHTTPClient>()->init();
-
-    QSettings settings;
-    // re-scan the aircraft list
-    m_aircraftModel->setPackageRoot(globals->packageRoot());
-
-    auto aircraftCache = LocalAircraftCache::instance();
-    aircraftCache->setPaths(settings.value("aircraft-paths").toStringList());
-    aircraftCache->scanDirs();
-
-    // re-set scenery dirs
-    flightgear::launcherSetSceneryPaths();
 }
 
 QmlAircraftInfo *LauncherController::selectedAircraftInfo() const

src/GUI/qml/SettingControl.qml

@@ -62,6 +62,9 @@ Item {
 
     function saveState()
     {
+        if (root.setting === "")
+            return;
+
         if (this.hasOwnProperty("value")) {
             _config.setValueForKey("", root.setting, this.value)
         } else {
@@ -71,10 +74,8 @@ Item {
 
     function restoreState()
     {
-        if (root.setting == "") {
+        if (root.setting === "")
-            console.warn("Missing setting key on " + label)
             return;
-        }
 
         if (!"value" in root) {
             console.warn("No value property on " + root);

src/GUI/qml/Settings.qml

@@ -309,7 +309,8 @@ Item {
                         label: qsTr("Download location")
                         description: qsTr("FlightGear stores downloaded files (scenery and aircraft) in this location. "
                                      + "Depending on your settings, it may grow to a considerable size (many gigabytes). "
-                                     + "If you change the download location, files will need to be downloaded again.")
+                                     + "If you change the download location, files will need to be downloaded again. "
+                                     + "When changing this setting, FlightGear will restart to use the new location correctly.")
                         advanced: true
                         chooseDirectory: true
                         defaultPath: _config.defaultDownloadDir
@@ -327,6 +328,12 @@ Item {
                             // value is changed.
                             _launcher.downloadDirChanged(path);
                         }
+
+                        function saveState()
+                        {
+                            // ensure this is a no-op, we write the value explicity
+                            // in LauncherController::downloadDirChanged
+                        }
                     }
                 ]