[xml] xmlStaticCopyNode and namespaces

[Charlie Bozeman <cbozeman HiWAAY net>]

My application copies branches from one part of a document to another
part using xmlDocCopyNode. Later when processing the new branches the
test for namespace equality fails:
if (node->ns == ns)
This failure is because the new branch nodes namespaces are copies of
the original namespace i.e. the namespace contents are equal but the
pointers are different. I traced the problem to xmlStaticCopyNode
starting at 2794:
    if (node->ns != NULL) {
        xmlNsPtr ns;

******************************************************************************
 the next line will always fail because there is no namespace in the
"ret" node
******************************************************************************
        ns = xmlSearchNs(doc, ret, node->ns->prefix);
        if (ns == NULL) {
            /*
             * Humm, we are copying an element whose namespace is
defined
             * out of the new tree scope. Search it in the original tree
             * and add it at the top of the new tree
             */
            ns = xmlSearchNs(node->doc, node, node->ns->prefix);
            if (ns != NULL) {
                xmlNodePtr root = ret;

                while (root->parent != NULL) root = root->parent;
                ret->ns = xmlNewNs(root, ns->href, ns->prefix);
            }
        } else {
            /*
             * reference the existing namespace definition in our own
tree.
             */
            ret->ns = ns;
        }

The attached patch checks if the intended copy is an out-of-tree copy
before making copies of the namespaces. 

Charlie Bozeman

Index: tree.c
===================================================================
RCS file: /cvs/gnome/gnome-xml/tree.c,v
retrieving revision 1.174
diff -c -r1.174 tree.c
*** tree.c      2002/01/06 23:05:13     1.174
--- tree.c      2002/01/10 03:07:37
***************
*** 2795,2804 ****
          ret->nsDef = xmlCopyNamespaceList(node->nsDef);
  
      if (node->ns != NULL) {
-         xmlNsPtr ns;
  
!       ns = xmlSearchNs(doc, ret, node->ns->prefix);
!       if (ns == NULL) {
            /*
             * Humm, we are copying an element whose namespace is defined
             * out of the new tree scope. Search it in the original tree
--- 2795,2807 ----
          ret->nsDef = xmlCopyNamespaceList(node->nsDef);
  
      if (node->ns != NULL) {
  
!         /*
!          * is this an out-of-tree copy
!          */
!         if (node->doc != doc) {
!             xmlNsPtr ns;
! 
            /*
             * Humm, we are copying an element whose namespace is defined
             * out of the new tree scope. Search it in the original tree
***************
*** 2815,2821 ****
            /*
             * reference the existing namespace definition in our own tree.
             */
!           ret->ns = ns;
        }
      }
      if (node->properties != NULL)
--- 2818,2824 ----
            /*
             * reference the existing namespace definition in our own tree.
             */
!           ret->ns = node->ns;
        }
      }
      if (node->properties != NULL)