[libxml2] Two smal namespace tweaks

[Daniel Veillard <veillard src gnome org>]

commit 81b961788a7eb01b46e6a4c44375585cd4e18056
Author: Daniel Veillard <veillard redhat com>
Date:   Mon Jul 22 13:01:11 2013 +0800

    Two smal namespace tweaks
    
    An improvement of the documentation, and an extra safety check
    for xmlSetNs()

 tree.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)
---
diff --git a/tree.c b/tree.c
index 7e5af26..7981771 100644
--- a/tree.c
+++ b/tree.c
@@ -717,8 +717,11 @@ xmlGetBufferAllocationScheme(void) {
  * Creation of a new Namespace. This function will refuse to create
  * a namespace with a similar prefix than an existing one present on this
  * node.
+ * Note that for a default namespace, @prefix should be NULL.
+ *
  * We use href==NULL in the case of an element creation where the namespace
  * was not defined.
+ *
  * Returns a new namespace pointer or NULL
  */
 xmlNsPtr
@@ -803,7 +806,9 @@ xmlSetNs(xmlNodePtr node, xmlNsPtr ns) {
 #endif
        return;
     }
-    node->ns = ns;
+    if ((node->type == XML_ELEMENT_NODE) ||
+        (node->type == XML_ATTRIBUTE_NODE))
+       node->ns = ns;
 }
 
 /**