Fix global menu for Xwayland windows

In a Plasma Wayland session, kded does not use the XCB QPA and so Qt doesn't
have an X11 connection. For X11 windows, it has to set some properties on
registration to make them known, so just make an X11 connection in that case.

appmenu/appmenu.cpp

@@ -42,7 +42,6 @@
 #include <kpluginfactory.h>
 #include <kpluginloader.h>
 #include <KSharedConfig>
-#include <KWindowSystem>
 
 #if HAVE_X11
 #include <QX11Info>
@@ -100,16 +99,32 @@ AppMenuModule::AppMenuModule(QObject* parent, const QList<QVariant>&)
     if (QDBusConnection::sessionBus().interface()->isServiceRegistered(QStringLiteral("org.kde.kappmenuview"))) {
         setupMenuImporter();
     }
+
+#if HAVE_X11
+    if (!QX11Info::connection()) {
+        m_xcbConn = xcb_connect(nullptr, nullptr);
+    }
+#endif
 }
 
-AppMenuModule::~AppMenuModule() = default;
+AppMenuModule::~AppMenuModule()
+{
+#if HAVE_X11
+    if (m_xcbConn) {
+        xcb_disconnect(m_xcbConn);
+    }
+#endif
+}
 
 void AppMenuModule::slotWindowRegistered(WId id, const QString &serviceName, const QDBusObjectPath &menuObjectPath)
 {
 #if HAVE_X11
-    if (KWindowSystem::isPlatformX11()) {
-        auto *c = QX11Info::connection();
+    auto *c = QX11Info::connection();
+    if (!c) {
+        c = m_xcbConn;
+    }
 
+    if(c) {
         static xcb_atom_t s_serviceNameAtom = XCB_ATOM_NONE;
         static xcb_atom_t s_objectPathAtom = XCB_ATOM_NONE;
 
@@ -126,8 +141,14 @@ void AppMenuModule::slotWindowRegistered(WId id, const QString &serviceName, con
                 }
             }
 
-            xcb_change_property(c, XCB_PROP_MODE_REPLACE, id, atom, XCB_ATOM_STRING,
+            auto cookie = xcb_change_property_checked(c, XCB_PROP_MODE_REPLACE, id, atom, XCB_ATOM_STRING,
                                     8, value.length(), value.constData());
+            xcb_generic_error_t *error;
+            if ((error = xcb_request_check(c, cookie))) {
+                qWarning() << "Got an error";
+                free(error);
+                return;
+            }
         };
 
         // TODO only set the property if it doesn't already exist

appmenu/appmenu.h

@@ -27,6 +27,11 @@
 #ifndef APPMENUMODULE_H
 #define APPMENUMODULE_H
 
+#include <config-X11.h>
+#ifdef HAVE_X11
+#include <xcb/xcb.h>
+#endif
+
 #include <kdedmodule.h>
 
 #include <QPointer>
@@ -92,6 +97,10 @@ private:
     AppmenuDBus *m_appmenuDBus;
     QDBusServiceWatcher *m_menuViewWatcher;
     QPointer<VerticalMenu> m_menu;
+
+#ifdef HAVE_X11
+    xcb_connection_t *m_xcbConn = nullptr;
+#endif
 };
 
 #endif

appmenu/menuimporter.cpp

@@ -67,9 +67,10 @@ void MenuImporter::RegisterWindow(WId id, const QDBusObjectPath& path)
 {
     KWindowInfo info(id, NET::WMWindowType, NET::WM2WindowClass);
     NET::WindowTypes mask = NET::AllTypesMask;
+    auto type = info.windowType(mask);
 
     // Menu can try to register, right click in gimp for example
-    if (info.windowType(mask) & (NET::Menu|NET::DropdownMenu|NET::PopupMenu)) {
+    if (type != NET::Unknown && (type & (NET::Menu|NET::DropdownMenu|NET::PopupMenu))) {
         return;
     }