wrappercamerabinsrc: Don't unset the video-source property on pipeline start

check_and_replace_src() was setting self->app_vid_src to NULL, which
means that an app setting the video-source property, and then starting,
stopping and re-starting the pipeline (ie to make changes to the
video-source-filter property) would after the restart no longer have
a video-source.

This patch fixes this by making gst_camerabin_setup_default_element return a
ref to the passed in user_element, rather then returning the user_element as
is, so that that ref can be passed on to the bin, and the app_vid_src ref
stays valid.

https://bugzilla.gnome.org/show_bug.cgi?id=701915

2 files changed, 8 insertions, 11 deletions

diff --git a/gst/camerabin2/camerabingeneral.c b/gst/camerabin2/camerabingeneral.c
index 43d681d4c..45a0df46a 100644
--- a/gst/camerabin2/camerabingeneral.c
+++ b/gst/camerabin2/camerabingeneral.c
@@ -172,11 +172,11 @@ gst_camerabin_create_and_add_element (GstBin * bin, const gchar * elem_name,
   return new_elem;
 }
 
-/* try to change the state of an element. This function returns the element when
- * the state change could be performed. When this function returns NULL an error
- * occured and the element is unreffed if @unref is TRUE. */
+/* try to change the state of an element. This function returns the element
+ * when the state change could be performed. When this function returns NULL
+ * an error occured and the element is unreffed. */
 static GstElement *
-try_element (GstElement * bin, GstElement * element, gboolean unref)
+try_element (GstElement * bin, GstElement * element)
 {
   GstStateChangeReturn ret;
 
@@ -185,8 +185,7 @@ try_element (GstElement * bin, GstElement * element, gboolean unref)
     if (ret == GST_STATE_CHANGE_FAILURE) {
       GST_DEBUG_OBJECT (bin, "failed state change..");
       gst_element_set_state (element, GST_STATE_NULL);
-      if (unref)
-        gst_object_unref (element);
+      gst_object_unref (element);
       element = NULL;
     }
   }
@@ -202,18 +201,18 @@ gst_camerabin_setup_default_element (GstBin * bin, GstElement * user_elem,
 
   if (user_elem) {
     GST_DEBUG_OBJECT (bin, "trying configured element");
-    elem = try_element (GST_ELEMENT_CAST (bin), user_elem, FALSE);
+    elem = try_element (GST_ELEMENT_CAST (bin), gst_object_ref (user_elem));
   } else {
     /* only try fallback if no specific sink was chosen */
     GST_DEBUG_OBJECT (bin, "trying %s", auto_elem_name);
     elem = gst_element_factory_make (auto_elem_name, instance_name);
-    elem = try_element (GST_ELEMENT_CAST (bin), elem, TRUE);
+    elem = try_element (GST_ELEMENT_CAST (bin), elem);
     if (elem == NULL) {
       /* if default sink from config.h is different then try it too */
       if (strcmp (default_elem_name, auto_elem_name)) {
         GST_DEBUG_OBJECT (bin, "trying %s", default_elem_name);
         elem = gst_element_factory_make (default_elem_name, instance_name);
-        elem = try_element (GST_ELEMENT_CAST (bin), elem, TRUE);
+        elem = try_element (GST_ELEMENT_CAST (bin), elem);
       }
     }
   }
diff --git a/gst/camerabin2/gstwrappercamerabinsrc.c b/gst/camerabin2/gstwrappercamerabinsrc.c
index 3e9dc5ac0..3f94428e2 100644
--- a/gst/camerabin2/gstwrappercamerabinsrc.c
+++ b/gst/camerabin2/gstwrappercamerabinsrc.c
@@ -489,8 +489,6 @@ check_and_replace_src (GstWrapperCameraBinSrc * self)
       }
     }
   }
-  /* we lost the reference */
-  self->app_vid_src = NULL;
 
   /* we listen for changes to max-zoom in the video src so that
    * we can proxy them to the basecamerasrc property */