On 6/12/2012 11:55, Ulrik Dickow wrote:
Patch 2 of 2 from http://bugs.winehq.org/show_bug.cgi?id=26226 .




    

+    /* Emit appropriate fixme or warning in case of unsupported or invalid namespace.
+     * The W3C spec would like us to exit earlier for attempts to redefine the namespace for
+     * the reserved "xmlns" attribute or prefix (http://www.w3.org/TR/xml-names/#ns-decl),
+     * like http://gdome2.cs.unibo.it/gtk-doc/gdome2-gdomeelement.html#GDOME-EL-SETATTRIBUTENS,
+     * but since native msxml3 accepts anything here, it's safest to just continue with warning.
+     */
The question is more like what libxml2 thinks about that. If it follows w3c here which is likely the question will be - won't it break somewhere internally in libxml2 code if we hack it that way?
+    if(namespaceURI && namespaceURI[0] && node_type != NODE_ELEMENT)
+    {
+        if(node_type == NODE_ATTRIBUTE)
+            switch((!strcmpW(name, xmlnsW) ||
+                    !strncmpW(name, xmlnscW, sizeof(xmlnscW)/sizeof(WCHAR))) +
+                   !strcmpW(namespaceURI, w3xmlns))
Could you please simplify that, it's a bit hard to read.
+     * Note: We would be more in line with the native msxml if we only detected a
+     * redundancy/conflict for prefixes existing on the element itself (in element->ns
+     * or in the linked list element->nsDef).  But as long as our *_get_xml() doesn't
+     * eliminate redundant namespace definitions in children, this behaviour may be
+     * an advantage in some cases.  As disadvantage is that we incorrectly regard the
+     * redefinition in element 'b' in '<a xmlns="x"><b xmlns="y"/></a>' as a conflict.
+     * Libxml2 currently doesn't have a function or option to only search for namespaces
+     * on the current node; but it would be easy to make a reduced version of xmlSearchNs
+     * (currently defined in http://git.gnome.org/browse/libxml2/tree/tree.c#n5871).
+     * However, most apps probably set the ns to y on node b creation, so no conflict here.
+     *
I don't think it's better to potentially break one thing while fixing the other. And I guess I like a thought on making xmlSearchNs version that will do what we want from it. Just to clarify - is that right that libxml2 problem here is a lack of some checks
that lead to duplication and conflicts later? (that are visible in doc dumps too)
+/* Convenient helper function for creating an attribute node in a given namespace.
+ * Note: CHECK_HR() should not be here, but in caller, to give optimal line number info.
+ */
You mean EXPECT_HR here I guess.
+static HRESULT create_attribute_ns(
+    IXMLDOMDocument *doc,
+    const char *attr_name,
+    const char *nsURI,
+    IXMLDOMAttribute **attr_ptr)
+{
+    HRESULT hr;
+    VARIANT var;
+    IXMLDOMNode *node;
+
+    V_VT(&var) = VT_I1;
+    V_I1(&var) = NODE_ATTRIBUTE;
+
+    hr = IXMLDOMDocument_createNode(doc, var, _bstr_(attr_name), _bstr_(nsURI), &node);
+    if (hr == S_OK)
+    {
+        IXMLDOMNode_QueryInterface(node, &IID_IXMLDOMAttribute, (void**) attr_ptr);
+        IXMLDOMNode_Release(node);
+    }
+    return hr;
+}
Please null out pointer in case of failure, or better always before createNode().