From 2ebebdbfbb7f5cfa7b438bb6b02fc723c9349d51 Mon Sep 17 00:00:00 2001
From: Alex Ashley <bugzilla@ashley-family.net>
Date: Wed, 19 Aug 2015 11:29:43 +0100
Subject: [PATCH] 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         | 42 +++++++++++++++++++----
 tests/check/elements/dash_mpd.c | 61 +++++++++++++++++++++++++++++++++
 2 files changed, 96 insertions(+), 7 deletions(-)

diff --git a/ext/dash/gstmpdparser.c b/ext/dash/gstmpdparser.c
index 98ef978249..e800d6b1f5 100644
--- a/ext/dash/gstmpdparser.c
+++ b/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 ();
-  int size;
+  const char *txt_encoding;
+  xmlCharEncodingHandlerPtr conv_hdlr = NULL;
+  xmlOutputBufferPtr out_buf;
 
-  size = xmlNodeDump (buffer, a_node->doc, a_node, 0,   /* indent */
-      0 /* format */ );
-  if (size > 0) {
-    *content = (gchar *) xmlBufferDetach (buffer);
+  txt_encoding = (const char *) a_node->doc->encoding;
+  if (txt_encoding != NULL) {
+    conv_hdlr = xmlFindCharEncodingHandler (txt_encoding);
+    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;
 }
 
diff --git a/tests/check/elements/dash_mpd.c b/tests/check/elements/dash_mpd.c
index ee5b6cbbd2..bbf27aa983 100644
--- a/tests/check/elements/dash_mpd.c
+++ b/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);