Make sure we don't use deleted memory in example

The view has a pointer to a QOpenGLTexture that is owned by the
buffer. Don't keep using that pointer after the buffer has deleted
it.

Task-number: QTBUG-69384
Change-Id: I48fd813e0dcb74db04d217238be7b0b6b345fc11
Reviewed-by: Johan Helsing <johan.helsing@qt.io>

1 files changed, 5 insertions, 2 deletions

diff --git a/examples/wayland/qwindow-compositor/compositor.cpp b/examples/wayland/qwindow-compositor/compositor.cpp
index 8ba8929e1..e224cd1c3 100644
--- a/examples/wayland/qwindow-compositor/compositor.cpp
+++ b/examples/wayland/qwindow-compositor/compositor.cpp
@@ -72,8 +72,11 @@ View::View(Compositor *compositor)
 
 QOpenGLTexture *View::getTexture()
 {
-    if (advance()) {
-        QWaylandBufferRef buf = currentBuffer();
+    bool newContent = advance();
+    QWaylandBufferRef buf = currentBuffer();
+    if (!buf.hasContent())
+        m_texture = nullptr;
+    if (newContent) {
         m_texture = buf.toOpenGLTexture();
         if (surface()) {
             m_size = surface()->size();