2 files changed, 10 insertions, 0 deletions
diff --git a/src/plugins/platformthemes/gtk3/qgtk3menu.cpp b/src/plugins/platformthemes/gtk3/qgtk3menu.cpp
index d264fabf0c..f464037989 100644
--- a/src/plugins/platformthemes/gtk3/qgtk3menu.cpp
+++ b/src/plugins/platformthemes/gtk3/qgtk3menu.cpp
@@ -85,6 +85,7 @@ QGtk3MenuItem::QGtk3MenuItem()
       m_checkable(false),
       m_checked(false),
       m_enabled(true),
+      m_exclusive(false),
       m_underline(false),
       m_invalid(true),
       m_menu(nullptr),
diff --git a/src/plugins/platformthemes/gtk3/qgtk3theme.cpp b/src/plugins/platformthemes/gtk3/qgtk3theme.cpp
index 93520344f8..6e9e89faf9 100644
--- a/src/plugins/platformthemes/gtk3/qgtk3theme.cpp
+++ b/src/plugins/platformthemes/gtk3/qgtk3theme.cpp
@@ -41,6 +41,7 @@
 #include "qgtk3dialoghelpers.h"
 #include "qgtk3menu.h"
 #include <QVariant>
+#include <QGuiApplication>
 
 #undef signals
 #include <gtk/gtk.h>
@@ -84,6 +85,14 @@ void gtkMessageHandler(const gchar *log_domain,
 
 QGtk3Theme::QGtk3Theme()
 {
+    // Ensure gtk uses the same windowing system, but let it
+    // fallback in case GDK_BACKEND environment variable
+    // filters the preferred one out
+    if (QGuiApplication::platformName().startsWith(QLatin1String("wayland")))
+        gdk_set_allowed_backends("wayland,x11");
+    else if (QGuiApplication::platformName() == QLatin1String("xcb"))
+        gdk_set_allowed_backends("x11,wayland");
+
     // gtk_init will reset the Xlib error handler, and that causes
     // Qt applications to quit on X errors. Therefore, we need to manually restore it.
     int (*oldErrorHandler)(Display *, XErrorEvent *) = XSetErrorHandler(nullptr);