Re: [xml] Invalid namespace definitions after namespace change

[Kasimier Buchcik <kbuchcik 4commerce de>]

Hi,

Jacek Konieczny wrote:
> Hello,
>
> I have a big problem with libxml2 python bindings. The problem also
> occurs in the C API, but it is easily fixable there (so it can be just
> called a 'feature').
>
> Here is the test case (python code):
>
> import libxml2
> doc=libxml2.parseDoc("<a xmlns='http://a/'><b xmlns='http://b/'/></a>")
> a = doc.getRootElement()
> b = a.children
> print `doc.serialize()`
> print "Ns of <b/>: %r" % (b.ns().content,)
> b.setNs(a.ns())
> print `doc.serialize()`
> print "Ns of <b/>: %r" % (b.ns().content,)
>
> The output is:
> '<?xml version="1.0"?>\n<a xmlns="http://a/";><b xmlns="http://b/"/></a>\n'
> Ns of <b/>: 'http://b/'
> '<?xml version="1.0"?>\n<a xmlns="http://a/";><b xmlns="http://b/"/></a>\n'
> Ns of <b/>: 'http://a/'
>
> As you can see I have a document with two nested elements with different
> namespaces and I change the namespace of the inner element to the names
> space of the outer one. Tree API (xmlNode.ns()) gives me right namespace
> information for the element <b/>. But there is still the old namespace
> declaration left on the element and it is included in the serialized
> output. Which makes the output wrong (nothing is changed, although
> I have changed the namespace of </b>).
>
> The biggest problem is, that I cannot fix that using only the Python
> API. xmlNode.reconciliateNs() does nothing about that.

There was a bug in xmlSearchNsByHref, which caused xmlReconciliateNs
to fail in this scenario. Fixed in CVS (tree.c 1.339).

> b.nsDefs().unlinkNode() causes Segmentation Fault and I have no idea
> what else could try to solve that.

xmlUnlinkNode() is not intended for namespace declarations. Bugzilla a
enhancement if you need a function for this.

> I have been using C code for namespace modifications, because I am able
> to remove unneeded namespace declaration by direct modifications of
> namespace declarations list on a node. But I would like to be able to do
> that on Python level or not be required to do that at all.

I'll attach the fix, in case you cannot wait for the anoncvs to reflect
the changes.

Czymaj sie,

Kasimier

Index: tree.c
===================================================================
RCS file: /cvs/gnome/libxml2/tree.c,v
retrieving revision 1.338
retrieving revision 1.339
diff -c -r1.338 -r1.339
*** tree.c      9 Feb 2005 16:48:53 -0000       1.338
--- tree.c      28 Feb 2005 10:28:20 -0000      1.339
***************
*** 5671,5677 ****
                  if ((cur->href != NULL) && (href != NULL) &&
                      (xmlStrEqual(cur->href, href))) {
                    if (((!is_attr) || (cur->prefix != NULL)) &&
!                       (xmlNsInScope(doc, orig, node, cur->href) == 1))
                        return (cur);
                  }
                  cur = cur->next;
--- 5671,5677 ----
                  if ((cur->href != NULL) && (href != NULL) &&
                      (xmlStrEqual(cur->href, href))) {
                    if (((!is_attr) || (cur->prefix != NULL)) &&
!                       (xmlNsInScope(doc, orig, node, cur->prefix) == 1))
                        return (cur);
                  }
                  cur = cur->next;
***************
*** 5682,5688 ****
                      if ((cur->href != NULL) && (href != NULL) &&
                          (xmlStrEqual(cur->href, href))) {
                        if (((!is_attr) || (cur->prefix != NULL)) &&
!                           (xmlNsInScope(doc, orig, node, cur->href) == 1))
                            return (cur);
                      }
                  }
--- 5682,5688 ----
                      if ((cur->href != NULL) && (href != NULL) &&
                          (xmlStrEqual(cur->href, href))) {
                        if (((!is_attr) || (cur->prefix != NULL)) &&
!                           (xmlNsInScope(doc, orig, node, cur->prefix) == 1))
                            return (cur);
                      }
                  }