1 files changed, 29 insertions, 1 deletions
diff --git a/src/compositor/compositor_api/qwaylandsurface.cpp b/src/compositor/compositor_api/qwaylandsurface.cpp
index bae6468ca..a8dc41fd5 100644
--- a/src/compositor/compositor_api/qwaylandsurface.cpp
+++ b/src/compositor/compositor_api/qwaylandsurface.cpp
@@ -322,7 +322,9 @@ QList<QWaylandOutput *> QWaylandSurface::outputs() const
     Q_D(const QWaylandSurface);
 
     QList<QWaylandOutput *> list;
-    Q_FOREACH (QtWayland::Output *output, d->outputs())
+    const QList<QtWayland::Output *> outputs = d->outputs();
+    list.reserve(outputs.count());
+    Q_FOREACH (QtWayland::Output *output, outputs)
         list.append(output->waylandOutput());
     return list;
 }
@@ -509,4 +511,30 @@ void QWaylandSurfacePrivate::setType(QWaylandSurface::WindowType type)
     }
 }
 
+class QWaylandUnmapLockPrivate
+{
+public:
+    QWaylandSurface *surface;
+};
+
+/*!
+    Constructs a QWaylandUnmapLock object.
+
+    The lock will act on the \a surface parameter, and will prevent the surface to
+    be unmapped, retaining the last valid buffer when the client attachs a NULL buffer.
+    The lock will be automatically released when deleted.
+*/
+QWaylandUnmapLock::QWaylandUnmapLock(QWaylandSurface *surface)
+                 : d(new QWaylandUnmapLockPrivate)
+{
+    d->surface = surface;
+    surface->handle()->addUnmapLock(this);
+}
+
+QWaylandUnmapLock::~QWaylandUnmapLock()
+{
+    d->surface->handle()->removeUnmapLock(this);
+    delete d;
+}
+
 QT_END_NAMESPACE