element: fix pad cleanup in dispose

In the dispose handler we first need to release all the request pads and then
remove the remaining pads. This is because it is possible that releasing the
request pad might also cleanly remove some of the other dynamic pads, like
what rtpsession does.

https://bugzilla.gnome.org/show_bug.cgi?id=677436

diff --git a/gst/gstelement.c b/gst/gstelement.c
index 60864a6..2962830 100644 (file)
--- a/gst/gstelement.c
+++ b/gst/gstelement.c
@@ -325,7 +325,7 @@ gst_element_release_request_pad (GstElement * element, GstPad * pad)
   /* if the element implements a custom release function we call that, else we
    * simply remove the pad from the element */
   if (oclass->release_pad)
-    (oclass->release_pad) (element, pad);
+    oclass->release_pad (element, pad);
   else
     gst_element_remove_pad (element, pad);
 }
@@ -2828,6 +2828,7 @@ gst_element_dispose (GObject * object)
   GstClock **clock_p;
   GstBus **bus_p;
   GstElementClass *oclass;
+  GList *walk;
 
   oclass = GST_ELEMENT_GET_CLASS (element);
 
@@ -2836,23 +2837,32 @@ gst_element_dispose (GObject * object)
   if (GST_STATE (element) != GST_STATE_NULL)
     goto not_null;
 
-  GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element,
-      "removing %d pads", g_list_length (element->pads));
-  /* first we break all our links with the outside */
-  while (element->pads && element->pads->data) {
-    GstPad *pad = GST_PAD_CAST (element->pads->data);
+  /* start by releasing all request pads, this might also remove some dynamic
+   * pads */
+  walk = element->pads;
+  while (walk) {
+    GstPad *pad = GST_PAD_CAST (walk->data);
+
+    walk = walk->next;
 
-    /* don't call _remove_pad with NULL */
     if (oclass->release_pad && GST_PAD_PAD_TEMPLATE (pad) &&
         GST_PAD_TEMPLATE_PRESENCE (GST_PAD_PAD_TEMPLATE (pad))
-        == GST_PAD_REQUEST)
-      (oclass->release_pad) (element, GST_PAD_CAST (element->pads->data));
-    else
-      gst_element_remove_pad (element, GST_PAD_CAST (element->pads->data));
+        == GST_PAD_REQUEST) {
+      GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element,
+          "removing request pad %s:%s", GST_DEBUG_PAD_NAME (pad));
+      oclass->release_pad (element, pad);
+    }
   }
-  if (G_UNLIKELY (element->pads != NULL)) {
-    g_critical ("could not remove pads from element %s",
-        GST_STR_NULL (GST_OBJECT_NAME (object)));
+  /* remove the remaining pads */
+  while (element->pads) {
+    GstPad *pad = GST_PAD_CAST (element->pads->data);
+    GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element,
+        "removing pad %s:%s", GST_DEBUG_PAD_NAME (pad));
+    if (!gst_element_remove_pad (element, pad)) {
+      /* only happens when someone unparented our pad.. */
+      g_critical ("failed to remove pad %s:%s", GST_DEBUG_PAD_NAME (pad));
+      break;
+    }
   }
 
   GST_OBJECT_LOCK (element);