splitmuxsink: Fix GObject warnings on shutdown.

Commit 83e718 added a pad template to splitmux request
pads, which means that GstElement now releases the pads on
dispose, but after having removed all elements in the bin
and unlinked them. Make sure we can handle cleanup in that case
without throwing assertions.

https://bugzilla.gnome.org/show_bug.cgi?id=773784

1 files changed, 18 insertions, 10 deletions

diff --git a/gst/multifile/gstsplitmuxsink.c b/gst/multifile/gstsplitmuxsink.c
index a7e2ddc94..b5a150995 100644
--- a/gst/multifile/gstsplitmuxsink.c
+++ b/gst/multifile/gstsplitmuxsink.c
@@ -278,11 +278,11 @@ gst_splitmux_sink_dispose (GObject * object)
 {
   GstSplitMuxSink *splitmux = GST_SPLITMUX_SINK (object);
 
-  G_OBJECT_CLASS (parent_class)->dispose (object);
-
   /* Calling parent dispose invalidates all child pointers */
   splitmux->sink = splitmux->active_sink = splitmux->muxer = splitmux->mq =
       NULL;
+
+  G_OBJECT_CLASS (parent_class)->dispose (object);
 }
 
 static void
@@ -1433,7 +1433,7 @@ static void
 gst_splitmux_sink_release_pad (GstElement * element, GstPad * pad)
 {
   GstSplitMuxSink *splitmux = (GstSplitMuxSink *) element;
-  GstPad *mqsink, *mqsrc, *muxpad;
+  GstPad *mqsink, *mqsrc = NULL, *muxpad = NULL;
   MqStreamCtx *ctx =
       (MqStreamCtx *) (g_object_get_qdata ((GObject *) (pad), PAD_CONTEXT));
 
@@ -1445,8 +1445,11 @@ gst_splitmux_sink_release_pad (GstElement * element, GstPad * pad)
   GST_INFO_OBJECT (pad, "releasing request pad");
 
   mqsink = gst_ghost_pad_get_target (GST_GHOST_PAD (pad));
-  mqsrc = mq_sink_to_src (splitmux->mq, mqsink);
-  muxpad = gst_pad_get_peer (mqsrc);
+  /* The ghostpad target might have disappeared during pipeline destruct */
+  if (mqsink)
+    mqsrc = mq_sink_to_src (splitmux->mq, mqsink);
+  if (mqsrc)
+    muxpad = gst_pad_get_peer (mqsrc);
 
   /* Remove the context from our consideration */
   splitmux->contexts = g_list_remove (splitmux->contexts, ctx);
@@ -1463,14 +1466,19 @@ gst_splitmux_sink_release_pad (GstElement * element, GstPad * pad)
     splitmux->reference_ctx = NULL;
 
   /* Release and free the mq input */
-  gst_element_release_request_pad (splitmux->mq, mqsink);
+  if (mqsink) {
+    gst_element_release_request_pad (splitmux->mq, mqsink);
+    gst_object_unref (mqsink);
+  }
 
   /* Release and free the muxer input */
-  gst_element_release_request_pad (splitmux->muxer, muxpad);
+  if (muxpad) {
+    gst_element_release_request_pad (splitmux->muxer, muxpad);
+    gst_object_unref (muxpad);
+  }
 
-  gst_object_unref (mqsink);
-  gst_object_unref (mqsrc);
-  gst_object_unref (muxpad);
+  if (mqsrc)
+    gst_object_unref (mqsrc);
 
   if (GST_PAD_PAD_TEMPLATE (pad) &&
       g_str_equal (GST_PAD_TEMPLATE_NAME_TEMPLATE (GST_PAD_PAD_TEMPLATE (pad)),