dashdemux: replace xmlNodeDump with xmlNodeDumpOutput

When running on an STB, the function
gst_mpdparser_get_xml_node_as_string causes a segmentation fault. This
code works correctly on a Linux desktop.

Looking at the libxml documentation, the xmlNodeDump is deprecated.
Replacing the use of xmlNodeDump with xmlNodeDumpOutput fixes the
segfault on the STB and removes the use of the deprecated function.

ext/dash/gstmpdparser.c

@@ -971,17 +971,45 @@ static gboolean
 gst_mpdparser_get_xml_node_as_string (xmlNode * a_node, gchar ** content)
 {
   gboolean exists = FALSE;
-  xmlBufferPtr buffer = xmlBufferCreate ();
+  const char *txt_encoding;
-  int size;
+  xmlCharEncodingHandlerPtr conv_hdlr = NULL;
+  xmlOutputBufferPtr out_buf;
 
-  size = xmlNodeDump (buffer, a_node->doc, a_node, 0,   /* indent */
+  txt_encoding = (const char *) a_node->doc->encoding;
-      0 /* format */ );
+  if (txt_encoding != NULL) {
-  if (size > 0) {
+    conv_hdlr = xmlFindCharEncodingHandler (txt_encoding);
-    *content = (gchar *) xmlBufferDetach (buffer);
+    if (conv_hdlr == NULL) {
+      GST_ERROR ("Unable to find encoder for encoding: %s", txt_encoding);
+      return FALSE;
+    }
+  }
+  out_buf = xmlAllocOutputBuffer (conv_hdlr);
+  g_assert (out_buf != NULL);
+  xmlNodeDumpOutput (out_buf, a_node->doc, a_node, 0, 0, txt_encoding);
+  xmlOutputBufferFlush (out_buf);
+#ifdef LIBXML2_NEW_BUFFER
+  if (xmlOutputBufferGetSize (out_buf) > 0) {
+    *content =
+        (gchar *) xmlStrndup (xmlOutputBufferGetContent (out_buf),
+        xmlOutputBufferGetSize (out_buf));
     exists = TRUE;
+  }
+#else
+  if (out_buf->conv && out_buf->conv->use > 0) {
+    *content =
+        (gchar *) xmlStrndup (out_buf->conv->content, out_buf->conv->use);
+    exists = TRUE;
+  } else if (out_buf->buffer && out_buf->buffer->use > 0) {
+    *content =
+        (gchar *) xmlStrndup (out_buf->buffer->content, out_buf->buffer->use);
+    exists = TRUE;
+  }
+#endif // LIBXML2_NEW_BUFFER
+  (void) xmlOutputBufferClose (out_buf);
+
+  if (exists) {
     GST_LOG (" - %s: %s", a_node->name, *content);
   }
-  xmlBufferFree (buffer);
   return exists;
 }
 

tests/check/elements/dash_mpd.c

@@ -1271,6 +1271,66 @@ GST_START_TEST
 
 GST_END_TEST;
 
+/*
+ * Test parsing ContentProtection element that has no value attribute
+ */
+GST_START_TEST (dash_mpdparser_contentProtection_no_value)
+{
+  GstPeriodNode *periodNode;
+  GstAdaptationSetNode *adaptationSet;
+  GstRepresentationBaseType *representationBase;
+  GstDescriptorType *contentProtection;
+  const gchar *xml =
+      "<?xml version=\"1.0\"?>"
+      "<MPD xmlns=\"urn:mpeg:dash:schema:mpd:2011\""
+      "     profiles=\"urn:mpeg:dash:profile:isoff-main:2011\">"
+      "  <Period>"
+      "    <AdaptationSet>"
+      "      <ContentProtection schemeIdUri=\"urn:mpeg:dash:mp4protection:2011\" value=\"cenc\"/>"
+      "      <ContentProtection xmlns:mas=\"urn:marlin:mas:1-0:services:schemas:mpd\" schemeIdUri=\"urn:uuid:5e629af5-38da-4063-8977-97ffbd9902d4\">"
+      "	      <mas:MarlinContentIds>"
+      "	        <mas:MarlinContentId>urn:marlin:kid:02020202020202020202020202020202</mas:MarlinContentId>"
+      "       </mas:MarlinContentIds>"
+      "     </ContentProtection>" "</AdaptationSet></Period></MPD>";
+
+  gboolean ret;
+  GstMpdClient *mpdclient = gst_mpd_client_new ();
+  gchar *str;
+
+  ret = gst_mpd_parse (mpdclient, xml, (gint) strlen (xml));
+  assert_equals_int (ret, TRUE);
+
+  periodNode = (GstPeriodNode *) mpdclient->mpd_node->Periods->data;
+  adaptationSet = (GstAdaptationSetNode *) periodNode->AdaptationSets->data;
+  representationBase = adaptationSet->RepresentationBase;
+  assert_equals_int (g_list_length (representationBase->ContentProtection), 2);
+  contentProtection =
+      (GstDescriptorType *) g_list_nth (representationBase->ContentProtection,
+      1)->data;
+  assert_equals_string (contentProtection->schemeIdUri,
+      "urn:uuid:5e629af5-38da-4063-8977-97ffbd9902d4");
+  fail_if (contentProtection->value == NULL);
+  g_print ("%s\n", contentProtection->value);
+  /* We can't do a simple compare of value (which should be an XML dump
+     of the ContentProtection element), because the whitespace
+     formatting from xmlDump might differ between versions of libxml */
+  str = strstr (contentProtection->value, "<ContentProtection");
+  fail_if (str == NULL);
+  str = strstr (contentProtection->value, "<mas:MarlinContentIds>");
+  fail_if (str == NULL);
+  str = strstr (contentProtection->value, "<mas:MarlinContentId>");
+  fail_if (str == NULL);
+  str =
+      strstr (contentProtection->value,
+      "urn:marlin:kid:02020202020202020202020202020202");
+  fail_if (str == NULL);
+  str = strstr (contentProtection->value, "</ContentProtection>");
+  fail_if (str == NULL);
+  gst_mpd_client_free (mpdclient);
+}
+
+GST_END_TEST;
+
 /*
  * Test parsing Period AdaptationSet Accessibility attributes
  *
@@ -4344,6 +4404,7 @@ dash_suite (void)
       dash_mpdparser_period_adaptationSet_representationBase_audioChannelConfiguration);
   tcase_add_test (tc_simpleMPD,
       dash_mpdparser_period_adaptationSet_representationBase_contentProtection);
+  tcase_add_test (tc_simpleMPD, dash_mpdparser_contentProtection_no_value);
   tcase_add_test (tc_simpleMPD,
       dash_mpdparser_period_adaptationSet_accessibility);
   tcase_add_test (tc_simpleMPD, dash_mpdparser_period_adaptationSet_role);