[libxml2] Support element node traversal in document fragments.

[Daniel Veillard <veillard src gnome org>]

commit 1db9969966aac1e844372e9b3288653a296e0365
Author: Kyle VanderBeek <kylev kylev com>
Date:   Tue Jul 29 00:32:15 2014 -0700

    Support element node traversal in document fragments.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=733900

 tree.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/tree.c b/tree.c
index 7d41481..53b956c 100644
--- a/tree.c
+++ b/tree.c
@@ -3456,6 +3456,7 @@ xmlChildElementCount(xmlNodePtr parent) {
         case XML_ELEMENT_NODE:
         case XML_ENTITY_NODE:
         case XML_DOCUMENT_NODE:
+        case XML_DOCUMENT_FRAG_NODE:
         case XML_HTML_DOCUMENT_NODE:
             cur = parent->children;
             break;
@@ -3491,6 +3492,7 @@ xmlFirstElementChild(xmlNodePtr parent) {
         case XML_ELEMENT_NODE:
         case XML_ENTITY_NODE:
         case XML_DOCUMENT_NODE:
+        case XML_DOCUMENT_FRAG_NODE:
         case XML_HTML_DOCUMENT_NODE:
             cur = parent->children;
             break;
@@ -3526,6 +3528,7 @@ xmlLastElementChild(xmlNodePtr parent) {
         case XML_ELEMENT_NODE:
         case XML_ENTITY_NODE:
         case XML_DOCUMENT_NODE:
+        case XML_DOCUMENT_FRAG_NODE:
         case XML_HTML_DOCUMENT_NODE:
             cur = parent->last;
             break;