fix ASAN detected stack-use-after-return error

Fixes: https://invent.kde.org/plasma/kwin/-/issues/129

src/keyboard_input.cpp

@@ -41,7 +41,7 @@ namespace KWin
 KeyboardInputRedirection::KeyboardInputRedirection(InputRedirection *parent)
     : QObject(parent)
     , m_input(parent)
-    , m_xkb(new Xkb(parent))
+    , m_xkb(new Xkb(parent, kwinApp()->followLocale1()))
 {
     connect(m_xkb.get(), &Xkb::ledsChanged, this, &KeyboardInputRedirection::ledsChanged);
     if (waylandServer()) {

src/main.h

@@ -380,6 +380,8 @@ private:
 
 inline static Application *kwinApp()
 {
+    Q_ASSERT(qobject_cast<Application *>(QCoreApplication::instance()));
+
     return static_cast<Application *>(QCoreApplication::instance());
 }
 

src/tabbox/tabboxhandler.cpp

@@ -396,9 +396,6 @@ void TabBoxHandler::show()
         d->show();
     }
     if (d->isHighlightWindows()) {
-        if (kwinApp()->x11Connection()) {
-            Xcb::sync();
-        }
         // TODO this should be
         // QMetaObject::invokeMethod(this, "initHighlightWindows", Qt::QueuedConnection);
         // but we somehow need to cross > 1 event cycle (likely because of queued invocation in the effects)

src/xkb.cpp

@@ -70,7 +70,7 @@ static void xkbLogHandler(xkb_context *context, xkb_log_level priority, const ch
     }
 }
 
-Xkb::Xkb(QObject *parent)
+Xkb::Xkb(QObject *parent, bool followLocale1)
     : QObject(parent)
     , m_context(xkb_context_new(XKB_CONTEXT_NO_FLAGS))
     , m_keymap(nullptr)
@@ -88,7 +88,7 @@ Xkb::Xkb(QObject *parent)
     , m_consumedModifiers(Qt::NoModifier)
     , m_keysym(XKB_KEY_NoSymbol)
     , m_leds()
-    , m_followLocale1(kwinApp()->followLocale1())
+    , m_followLocale1(followLocale1)
 {
     qRegisterMetaType<KWin::LEDs>();
     if (!m_context) {

src/xkb.h

@@ -42,7 +42,7 @@ class KWIN_EXPORT Xkb : public QObject
 {
     Q_OBJECT
 public:
-    Xkb(QObject *parent = nullptr);
+    Xkb(QObject *parent = nullptr, bool followLocale1 = false);
     ~Xkb() override;
     void setConfig(const KSharedConfigPtr &config);
     void setNumLockConfig(const KSharedConfigPtr &config);