gstxml: fix (de)serialisation of properties of type GstStructure

souphttpsrc has a property of type GstStructure, which causes an
assertion when serialising it to xml. Fixes #585137.

2 files changed, 19 insertions, 3 deletions

diff --git a/gst/gstelement.c b/gst/gstelement.c
index af83fcecb..4fc095b92 100644
--- a/gst/gstelement.c
+++ b/gst/gstelement.c
@@ -89,6 +89,7 @@
 #include "gstevent.h"
 #include "gstutils.h"
 #include "gstinfo.h"
+#include "gstvalue.h"
 #include "gst-i18n-lib.h"
 
 /* Element signals and args */
@@ -2958,7 +2959,13 @@ gst_element_save_thyself (GstObject * object, xmlNodePtr parent)
       else if (G_IS_PARAM_SPEC_INT64 (spec))
         contents = g_strdup_printf ("%" G_GINT64_FORMAT,
             g_value_get_int64 (&value));
-      else
+      else if (GST_VALUE_HOLDS_STRUCTURE (&value)) {
+        if (g_value_get_boxed (&value) != NULL) {
+          contents = g_strdup_value_contents (&value);
+        } else {
+          contents = g_strdup ("NULL");
+        }
+      } else
         contents = g_strdup_value_contents (&value);
 
       xmlNewChild (param, NULL, (xmlChar *) "value", (xmlChar *) contents);
diff --git a/gst/gstutils.c b/gst/gstutils.c
index 1b74d6286..0f49340e6 100644
--- a/gst/gstutils.c
+++ b/gst/gstutils.c
@@ -140,16 +140,25 @@ gst_util_set_object_arg (GObject * object, const gchar * name,
 
   value_type = G_PARAM_SPEC_VALUE_TYPE (pspec);
 
-  GST_DEBUG ("pspec->flags is %d, pspec->value_type is %d",
-      pspec->flags, (gint) value_type);
+  GST_DEBUG ("pspec->flags is %d, pspec->value_type is %s",
+      pspec->flags, g_type_name (value_type));
 
   if (!(pspec->flags & G_PARAM_WRITABLE))
     return;
 
   g_value_init (&v, value_type);
+
+  /* special case for element <-> xml (de)serialisation */
+  if (GST_VALUE_HOLDS_STRUCTURE (&v) && strcmp (value, "NULL") == 0) {
+    g_value_set_boxed (&v, NULL);
+    goto done;
+  }
+
   if (!gst_value_deserialize (&v, value))
     return;
 
+done:
+
   g_object_set_property (object, pspec->name, &v);
   g_value_unset (&v);
 }