From b4d9d9d9f8dd7c0ed1fcd8336a71b6c44ef28655 Mon Sep 17 00:00:00 2001
From: Chris Bass <floobleflam@gmail.com>
Date: Fri, 7 Apr 2017 10:16:46 +0100
Subject: [PATCH] ttmlparse: don't filter out untimed whitespace

Significant whitespace in elements that don't have begin/end values
should inherit timing from its parent, or if no its parents have no
timing, from the document's Root Temporal Extent. Currently, such
whitespace is removed, which is not spec-compliant. Fix this by
retaining whitespace in content nodes, and assigning a Root Temporal
Extent of 24 hours to any significant whitespace whose parents have no
associated timing.

https://bugzilla.gnome.org/show_bug.cgi?id=781027
---
 ext/ttml/ttmlparse.c | 43 +++++++++++++++++++++++++++++++++++++------
 1 file changed, 37 insertions(+), 6 deletions(-)

diff --git a/ext/ttml/ttmlparse.c b/ext/ttml/ttmlparse.c
index 535fde1..016523c 100644
--- a/ext/ttml/ttmlparse.c
+++ b/ext/ttml/ttmlparse.c
@@ -42,6 +42,7 @@
 #define DEFAULT_CELLRES_X 32
 #define DEFAULT_CELLRES_Y 15
 #define MAX_FONT_FAMILY_NAME_LENGTH 128
+#define NSECONDS_IN_DAY 24 * 3600 * GST_SECOND
 
 GST_DEBUG_CATEGORY_EXTERN (ttmlparse_debug);
 #define GST_CAT_DEFAULT ttmlparse_debug
@@ -424,7 +425,7 @@ ttml_parse_body (const xmlNode * node)
 
   for (node = node->children; node != NULL; node = node->next) {
     GNode *descendants = NULL;
-    if (!xmlIsBlankNode (node) && (descendants = ttml_parse_body (node)))
+    if ((descendants = ttml_parse_body (node)))
       g_node_append (ret, descendants);
   }
 
@@ -1018,8 +1019,9 @@ ttml_resolve_element_timings (GNode * node, gpointer data)
 
   if (!GST_CLOCK_TIME_IS_VALID (element->begin)) {
     GST_CAT_WARNING (ttmlparse_debug,
-        "No timing found for element. Removing from tree...");
-    g_node_unlink (node);
+        "No timing found for element; setting to Root Temporal Extent.");
+    leaf->begin = 0;
+    leaf->end = NSECONDS_IN_DAY;
   } else {
     leaf->begin = element->begin;
     leaf->end = element->end;
@@ -1276,6 +1278,34 @@ ttml_handle_whitespace (GNode * tree)
 }
 
 
+static GNode *
+ttml_filter_content_nodes (GNode * node)
+{
+  GNode *child, *next_child;
+  TtmlElement *element = node->data;
+  TtmlElement *parent = node->parent ? node->parent->data : NULL;
+
+  child = node->children;
+  next_child = child ? child->next : NULL;
+  while (child) {
+    ttml_filter_content_nodes (child);
+    child = next_child;
+    next_child = child ? child->next : NULL;
+  }
+
+  /* Only text content in <p>s and <span>s is significant. */
+  if (element->type == TTML_ELEMENT_TYPE_ANON_SPAN
+      && parent->type != TTML_ELEMENT_TYPE_P
+      && parent->type != TTML_ELEMENT_TYPE_SPAN) {
+    ttml_delete_element (element);
+    g_node_destroy (node);
+    node = NULL;
+  }
+
+  return node;
+}
+
+
 /* Store child elements of @node with name @element_name in @table, as long as
  * @table doesn't already contain an element with the same ID. */
 static void
@@ -1357,6 +1387,7 @@ ttml_copy_element (const TtmlElement * element)
   ret->type = element->type;
   if (element->id)
     ret->id = g_strdup (element->id);
+  ret->whitespace_mode = element->whitespace_mode;
   if (element->styles)
     ret->styles = g_strdupv (element->styles);
   if (element->region)
@@ -1697,7 +1728,7 @@ ttml_assign_region_times (GList * region_trees, GstClockTime doc_begin,
        * any real-world stream. */
       region->begin = (doc_begin != GST_CLOCK_TIME_NONE) ? doc_begin : 0;
       region->end = (doc_duration != GST_CLOCK_TIME_NONE) ?
-          region->begin + doc_duration : 24 * 3600 * GST_SECOND;
+          region->begin + doc_duration : NSECONDS_IN_DAY;
     }
   }
 }
@@ -1737,8 +1768,7 @@ ttml_parse (const gchar * input, GstClockTime begin, GstClockTime duration)
       (GDestroyNotify) ttml_delete_element);
 
   /* Parse input. */
-  doc = xmlReadMemory (input, strlen (input), "any_doc_name", NULL,
-      XML_PARSE_NOBLANKS);
+  doc = xmlReadMemory (input, strlen (input), "any_doc_name", NULL, 0);
   if (!doc) {
     GST_CAT_ERROR (ttmlparse_debug, "Failed to parse document.");
     return NULL;
@@ -1792,6 +1822,7 @@ ttml_parse (const gchar * input, GstClockTime begin, GstClockTime duration)
 
     ttml_inherit_whitespace_mode (body_tree, doc_whitespace_mode);
     ttml_handle_whitespace (body_tree);
+    ttml_filter_content_nodes (body_tree);
     if (GST_CLOCK_TIME_IS_VALID (begin) && GST_CLOCK_TIME_IS_VALID (duration))
       ttml_apply_time_window (body_tree, begin, begin + duration);
     ttml_resolve_timings (body_tree);
-- 
2.7.4