GStreamer camerabin: return the proper camera source

 - return m_cameraSrc for function cameraSource() instead of m_videoSrc.
   m_videoSrc is not always assigned(default 0), it will crash on:
   if (g_object_class_find_property(
      G_OBJECT_GET_CLASS(m_session->cameraSource()), "exposure-mode")) {
   And as the function name says, it would be better to return the
   value m_cameraSrc.
 - make sure pointers are not NULL before using them.

Change-Id: I8a56db34a805724b428409b87de7d072ee7bfa57
Reviewed-by: Yoann Lopes <yoann.lopes@qt.io>

3 files changed, 19 insertions, 7 deletions

diff --git a/src/plugins/gstreamer/camerabin/camerabinlocks.cpp b/src/plugins/gstreamer/camerabin/camerabinlocks.cpp
index e6fe9a309..2f44ec057 100644
--- a/src/plugins/gstreamer/camerabin/camerabinlocks.cpp
+++ b/src/plugins/gstreamer/camerabin/camerabinlocks.cpp
@@ -65,9 +65,12 @@ QCamera::LockTypes CameraBinLocks::supportedLocks() const
     if (GstPhotography *photography = m_session->photography()) {
         if (gst_photography_get_capabilities(photography) & GST_PHOTOGRAPHY_CAPS_WB_MODE)
             locks |= QCamera::LockWhiteBalance;
-        if (g_object_class_find_property(
-                    G_OBJECT_GET_CLASS(m_session->cameraSource()), "exposure-mode")) {
-            locks |= QCamera::LockExposure;
+
+    if (GstElement *source = m_session->cameraSource()) {
+            if (g_object_class_find_property(
+                        G_OBJECT_GET_CLASS(source), "exposure-mode")) {
+                locks |= QCamera::LockExposure;
+            }
         }
     }
 #endif
@@ -195,9 +198,13 @@ bool CameraBinLocks::isExposureLocked() const
 
 void CameraBinLocks::lockExposure(QCamera::LockChangeReason reason)
 {
+    GstElement *source = m_session->cameraSource();
+    if (!source)
+        return;
+
     m_pendingLocks &= ~QCamera::LockExposure;
     g_object_set(
-                G_OBJECT(m_session->cameraSource()),
+                G_OBJECT(source),
                 "exposure-mode",
                 GST_PHOTOGRAPHY_EXPOSURE_MODE_MANUAL,
                 NULL);
@@ -206,8 +213,12 @@ void CameraBinLocks::lockExposure(QCamera::LockChangeReason reason)
 
 void CameraBinLocks::unlockExposure(QCamera::LockStatus status, QCamera::LockChangeReason reason)
 {
+    GstElement *source = m_session->cameraSource();
+    if (!source)
+        return;
+
     g_object_set(
-                G_OBJECT(m_session->cameraSource()),
+                G_OBJECT(source),
                 "exposure-mode",
                 GST_PHOTOGRAPHY_EXPOSURE_MODE_AUTO,
                 NULL);
diff --git a/src/plugins/gstreamer/camerabin/camerabinsession.cpp b/src/plugins/gstreamer/camerabin/camerabinsession.cpp
index 3dd200c54..96b31e1b3 100644
--- a/src/plugins/gstreamer/camerabin/camerabinsession.cpp
+++ b/src/plugins/gstreamer/camerabin/camerabinsession.cpp
@@ -514,7 +514,8 @@ GstElement *CameraBinSession::buildCameraSource()
                 if (!m_videoSrc)
                     m_videoSrc = gst_element_factory_make("v4l2src", "camera_source");
 
-                g_object_set(G_OBJECT(m_cameraSrc), "video-source", m_videoSrc, NULL);
+                if (m_videoSrc)
+                    g_object_set(G_OBJECT(m_cameraSrc), "video-source", m_videoSrc, NULL);
             }
 
             if (m_videoSrc)
diff --git a/src/plugins/gstreamer/camerabin/camerabinsession.h b/src/plugins/gstreamer/camerabin/camerabinsession.h
index dda900a8b..ade8916ba 100644
--- a/src/plugins/gstreamer/camerabin/camerabinsession.h
+++ b/src/plugins/gstreamer/camerabin/camerabinsession.h
@@ -91,7 +91,7 @@ public:
     GstPhotography *photography();
 #endif
     GstElement *cameraBin() { return m_camerabin; }
-    GstElement *cameraSource() { return m_videoSrc; }
+    GstElement *cameraSource() { return m_cameraSrc; }
     QGstreamerBusHelper *bus() { return m_busHelper; }
 
     QList< QPair<int,int> > supportedFrameRates(const QSize &frameSize, bool *continuous) const;