qv4l2: fix segmentation fault when compiled without ALSA support.

If opening the video device fails, then qv4l2 attempts to disable
two alsa widgets. If qv4l2 was compiled without alsa support, then
those widget pointers are NULL and you get a segfault.

Add the proper #ifdef so this is only done if alsa support was
compiled in.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>

diff --git a/utils/qv4l2/qv4l2.cpp b/utils/qv4l2/qv4l2.cpp
index bcce927..5f26ff4 100644 (file)
--- a/utils/qv4l2/qv4l2.cpp
+++ b/utils/qv4l2/qv4l2.cpp
@@ -208,8 +208,10 @@ void ApplicationWindow::setDevice(const QString &device, bool rawOpen)
        connect(m_sigMapper, SIGNAL(mapped(int)), this, SLOT(ctrlAction(int)));
 
        if (!open(device, !rawOpen)) {
+#ifdef HAVE_ALSA
                m_showAllAudioAct->setEnabled(false);
                m_audioBufferAct->setEnabled(false);
+#endif
                return;
        }