[rhythmbox] playbin2: ignore notify::source while changing to NULL

[Jonathan Matthew <jmatthew src gnome org>]

commit 1f9e7223f6ca55f6eb580b8ee95b459d98dc6031
Author: Jonathan Matthew <jonathan d14n org>
Date:   Sun Apr 22 11:48:44 2012 +1000

    playbin2: ignore notify::source while changing to NULL

 backends/gstreamer/rb-player-gst.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/backends/gstreamer/rb-player-gst.c b/backends/gstreamer/rb-player-gst.c
index 70e3db3..d48634e 100644
--- a/backends/gstreamer/rb-player-gst.c
+++ b/backends/gstreamer/rb-player-gst.c
@@ -378,6 +378,7 @@ start_state_change (RBPlayerGst *mp, GstState state, enum StateChangeAction acti
 {
 	GstStateChangeReturn scr;
 
+	rb_debug ("changing state to %s", gst_element_state_get_name (state));
 	mp->priv->state_change_action = action;
 	scr = gst_element_set_state (mp->priv->playbin, state);
 	if (scr == GST_STATE_CHANGE_SUCCESS) {
@@ -608,6 +609,12 @@ static void
 source_notify_cb (GObject *object, GParamSpec *pspec, RBPlayerGst *player)
 {
 	GstElement *source;
+
+	if (player->priv->uri == NULL) {
+		rb_debug ("got notify::source while changing to NULL");
+		return;
+	}
+
 	g_object_get (object, "source", &source, NULL);
 
 	g_signal_emit (player, signals[PREPARE_SOURCE], 0, player->priv->uri, source);