Make xdg-surface acknowledged configure serials double-buffered state

This will be needed to delay applying surface state.

src/wayland/autotests/client/test_xdg_shell.cpp

@@ -544,6 +544,7 @@ void XdgShellTest::testConfigureStates()
     QVERIFY(ackSpy.isValid());
 
     xdgSurface->ackConfigure(configureSpy.first().at(2).value<quint32>());
+    surface->commit(Surface::CommitFlag::None);
     QVERIFY(ackSpy.wait());
     QCOMPARE(ackSpy.count(), 1);
     QCOMPARE(ackSpy.first().first().value<quint32>(), configureSpy.first().at(2).value<quint32>());
@@ -590,6 +591,7 @@ void XdgShellTest::testConfigureMultipleAcks()
     QCOMPARE(xdgSurface->size(), QSize(30, 40));
 
     xdgSurface->ackConfigure(serial3);
+    surface->commit(Surface::CommitFlag::None);
     QVERIFY(ackSpy.wait());
     QCOMPARE(ackSpy.count(), 1);
     QCOMPARE(ackSpy.last().first().value<quint32>(), serial3);

src/wayland/xdgshell_interface.cpp

@@ -151,17 +151,26 @@ XdgSurfaceInterfacePrivate::XdgSurfaceInterfacePrivate(XdgSurfaceInterface *xdgS
 
 void XdgSurfaceInterfacePrivate::commit()
 {
-    if (current.windowGeometry != next.windowGeometry) {
+    if (next.acknowledgedConfigureIsSet) {
+        current.acknowledgedConfigure = next.acknowledgedConfigure;
+        next.acknowledgedConfigureIsSet = false;
+        Q_EMIT q->configureAcknowledged(current.acknowledgedConfigure);
+    }
+
+    if (next.windowGeometryIsSet) {
         current.windowGeometry = next.windowGeometry;
+        next.windowGeometryIsSet = false;
         Q_EMIT q->windowGeometryChanged(current.windowGeometry);
     }
+
     isMapped = surface->buffer();
 }
 
 void XdgSurfaceInterfacePrivate::reset()
 {
     isConfigured = false;
-    current = next = State();
+    current = XdgSurfaceState{};
+    next = XdgSurfaceState{};
     Q_EMIT q->resetOccurred();
 }
 
@@ -253,12 +262,14 @@ void XdgSurfaceInterfacePrivate::xdg_surface_set_window_geometry(Resource *resou
     }
 
     next.windowGeometry = QRect(x, y, width, height);
+    next.windowGeometryIsSet = true;
 }
 
 void XdgSurfaceInterfacePrivate::xdg_surface_ack_configure(Resource *resource, uint32_t serial)
 {
     Q_UNUSED(resource)
-    Q_EMIT q->configureAcknowledged(serial);
+    next.acknowledgedConfigure = serial;
+    next.acknowledgedConfigureIsSet = true;
 }
 
 XdgSurfaceInterface::XdgSurfaceInterface(XdgShellInterface *shell, SurfaceInterface *surface,

src/wayland/xdgshell_interface_p.h

@@ -84,6 +84,14 @@ protected:
     void xdg_positioner_set_parent_configure(Resource *resource, uint32_t serial) override;
 };
 
+struct XdgSurfaceState
+{
+    QRect windowGeometry;
+    quint32 acknowledgedConfigure;
+    bool acknowledgedConfigureIsSet : 1 = false;
+    bool windowGeometryIsSet : 1 = false;
+};
+
 class XdgSurfaceInterfacePrivate : public QtWaylandServer::xdg_surface
 {
 public:
@@ -100,13 +108,8 @@ public:
     bool isMapped = false;
     bool isConfigured = false;
 
-    struct State
-    {
-        QRect windowGeometry;
-    };
-
-    State next;
-    State current;
+    XdgSurfaceState next;
+    XdgSurfaceState current;
 
     static XdgSurfaceInterfacePrivate *get(XdgSurfaceInterface *surface);