Fixed crash in Phonon MMF backend during application shutdown

During application shutdown, DsaVideoPlayer::handleVideoWindowChanged
is called.  At this point, the application's main window has been closed
and therefore QApplication::activeWindow() returns 0.  This leads to a
crash.

This patch ensures that a null return value from
QApplication::activeWindow(), and the resulting zero value of
DsaVideoPlayer::m_window, are handled gracefully.

Reviewed-by: Frans Englich

1 files changed, 7 insertions, 1 deletions

diff --git a/src/3rdparty/phonon/mmf/videoplayer_dsa.cpp b/src/3rdparty/phonon/mmf/videoplayer_dsa.cpp
index 21cdb16..732d2d9 100644
--- a/src/3rdparty/phonon/mmf/videoplayer_dsa.cpp
+++ b/src/3rdparty/phonon/mmf/videoplayer_dsa.cpp
@@ -162,7 +162,10 @@ void MMF::DsaVideoPlayer::prepareCompleted()
 void MMF::DsaVideoPlayer::handleVideoWindowChanged()
 {
     if (!m_window) {
-        m_window = QApplication::activeWindow()->effectiveWinId()->DrawableWindow();
+        if (QWidget *window = QApplication::activeWindow())
+            m_window = window->effectiveWinId()->DrawableWindow();
+        else
+            m_window = 0;
         m_videoScreenRect = TRect();
     }
 
@@ -213,6 +216,9 @@ void MMF::DsaVideoPlayer::handleParametersChanged(VideoParameters parameters)
     TRACE_CONTEXT(DsaVideoPlayer::handleParametersChanged, EVideoInternal);
     TRACE_ENTRY_0();
 
+    if (!m_window)
+        return;
+
 #ifndef QT_NO_DEBUG
     getDsaRegion(m_wsSession, *m_window);
 #endif