Fix reset-data-path dialog logic

Use correct root path key in QSettings, everywhere
Use the direct Win32 API until Qt wrapper is fixed.

src/GUI/LauncherController.cxx

@@ -53,6 +53,7 @@
 #include "FlightPlanController.hxx"
 #include "ModelDataExtractor.hxx"
 #include "CarriersLocationModel.hxx"
+#include "SetupRootDialog.hxx"
 
 using namespace simgear::pkg;
 
@@ -767,7 +768,7 @@ void LauncherController::requestChangeDataPath()
 {
 	QString currentLocText;
 	QSettings settings;
-	QString root = settings.value("fg-root").toString();
+	QString root = settings.value(SetupRootDialog::rootPathKey()).toString();
 	if (root.isNull()) {
 		currentLocText = tr("Currently the built-in data files are being used");
 	}
@@ -791,12 +792,7 @@ void LauncherController::requestChangeDataPath()
 		return;
 	}
 
-	{
+    SetupRootDialog::askRootOnNextLaunch();
-		QSettings settings;
-		// set the option to the magic marker value
-		settings.setValue("fg-root", "!ask");
-	} // scope the ensure settings are written nicely
-
     flightgear::restartTheApp();
 }
 

src/GUI/QtLauncher.cxx

@@ -356,19 +356,22 @@ void initQSettings()
 bool checkKeyboardModifiersForSettingFGRoot()
 {
     initQSettings();
-
+#if defined(Q_OS_WIN)
+    const auto altState = GetAsyncKeyState(VK_MENU);
+    const auto shiftState = GetAsyncKeyState(VK_SHIFT);
+    if ((altState < 0) || (shiftState < 0))
+#else
     Qt::KeyboardModifiers mods = qApp->queryKeyboardModifiers();
-    if (mods & (Qt::AltModifier | Qt::ShiftModifier)) {
+    if (mods & (Qt::AltModifier | Qt::ShiftModifier))
+#endif
+    {
         qWarning() << "Alt/shift pressed during launch";
-        QSettings settings;
-        settings.setValue("fg-root", "!ask");
         return true;
     }
 
     return false;
 }
 
-
 void restartTheApp()
 {
     QStringList fgArgs;

src/GUI/SetupRootDialog.cxx

@@ -40,7 +40,9 @@
 #include <Include/version.h>
 #include <Viewer/WindowBuilder.hxx>
 
-static QString rootPathKey()
+#include "QtLauncher.hxx"
+
+QString SetupRootDialog::rootPathKey()
 {
     // return a settings key like fg-root-2018-3-0
     return QString("fg-root-") + QString(FLIGHTGEAR_VERSION).replace('.', '-');
@@ -99,7 +101,8 @@ SGPath SetupRootDialog::restoreUserSelectedRoot()
 {
     QSettings settings;
     QString path = settings.value(rootPathKey()).toString();
-    if (path == "!ask") {
+	bool ask = flightgear::checkKeyboardModifiersForSettingFGRoot();
+    if (ask || (path == QStringLiteral("!ask"))) {
         bool ok = runDialog(ManualChoiceRequested);
         Q_ASSERT(ok);
         // run dialog either exit()s or sets fg_root, so this
@@ -108,7 +111,7 @@ SGPath SetupRootDialog::restoreUserSelectedRoot()
     }
 
     if (path.isEmpty()) {
-        return std::string(); // use the default path
+        return SGPath{}; // use the default path
     }
 
     if (validatePath(path) && validateVersion(path)) {
@@ -118,7 +121,7 @@ SGPath SetupRootDialog::restoreUserSelectedRoot()
         // let's see if the default root is acceptable, in which case we will
         // switch to it. (This gives a more friendly upgrade experience).
         if (defaultRootAcceptable()) {
-            return std::string(); // use the default path
+            return SGPath{}; // use the default path
         }
 
         // okay, we don't have an acceptable FG_DATA anywhere we can find, we
@@ -131,6 +134,13 @@ SGPath SetupRootDialog::restoreUserSelectedRoot()
     }
 }
 
+void SetupRootDialog::askRootOnNextLaunch()
+{
+    QSettings settings;
+    // set the option to the magic marker value
+    settings.setValue(rootPathKey(), "!ask");
+}
+
 bool SetupRootDialog::validatePath(QString path)
 {
     // check assorted files exist in the root location, to avoid any chance of
@@ -216,7 +226,7 @@ void SetupRootDialog::onUseDefaults()
     m_browsedPath = QString::fromStdString(r.utf8Str());
     globals->set_fg_root(r);
     QSettings settings;
-    settings.remove("fg-root"); // remove any setting
+    settings.remove(rootPathKey()); // remove any setting
     accept();
 }
 

src/GUI/SetupRootDialog.hxx

@@ -41,6 +41,10 @@ public:
     static bool runDialog(bool usingDefaultRoot);
 
     static SGPath restoreUserSelectedRoot();
+    
+    static void askRootOnNextLaunch();
+    
+    static QString rootPathKey();
 private slots:
 
     void onBrowse();

src/Main/main.cxx

@@ -629,7 +629,6 @@ int fgMainInit( int argc, char **argv )
 
 #if defined(HAVE_QT)
     if (showLauncher) {
-        flightgear::checkKeyboardModifiersForSettingFGRoot();
         if (!flightgear::runLauncherDialog()) {
             return EXIT_SUCCESS;
         }