1 files changed, 23 insertions, 0 deletions
diff --git a/src/plugins/platformthemes/gtk3/qgtk3theme.cpp b/src/plugins/platformthemes/gtk3/qgtk3theme.cpp
index 93520344f8..03f19a5b70 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);
@@ -100,6 +109,20 @@ QGtk3Theme::QGtk3Theme()
 
     /* Use our custom log handler. */
     g_log_set_handler("Gtk", G_LOG_LEVEL_MESSAGE, gtkMessageHandler, nullptr);
+
+    /* Set XCURSOR_SIZE and XCURSOR_THEME for Wayland sessions */
+    if (QGuiApplication::platformName().startsWith(QLatin1String("wayland"))) {
+        if (qEnvironmentVariableIsEmpty("XCURSOR_SIZE")) {
+            const int cursorSize = gtkSetting<gint>("gtk-cursor-theme-size");
+            if (cursorSize > 0)
+                qputenv("XCURSOR_SIZE", QByteArray::number(cursorSize));
+        }
+        if (qEnvironmentVariableIsEmpty("XCURSOR_THEME")) {
+            const QString cursorTheme = gtkSetting("gtk-cursor-theme-name");
+            if (!cursorTheme.isEmpty())
+                qputenv("XCURSOR_THEME", cursorTheme.toUtf8());
+        }
+    }
 }
 
 static inline QVariant gtkGetLongPressTime()