c14n.c

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    }
    if((ns != NULL) && !xmlC14NIsXmlNs(ns)) {
	if(visible && xmlC14NIsVisible(ctx, ns, cur)) { 
	    if(!xmlExcC14NVisibleNsStackFind(ctx->ns_rendered, ns, ctx)) {
		xmlListInsert(list, ns);
	    }
	}
	if(visible) {
    	    xmlC14NVisibleNsStackAdd(ctx->ns_rendered, ns, cur); 
	}
	if(xmlStrlen(ns->prefix) == 0) {
	    has_empty_ns = 1;
	}
    }
    
        
    /* add attributes */
    for(attr = cur->properties; attr != NULL; attr = attr->next) {
        /* 
         * we need to check that attribute is visible and has non
         * default namespace (XML Namespaces: "default namespaces 
    	 * do not apply directly to attributes")	 
         */
	if((attr->ns != NULL) && !xmlC14NIsXmlNs(attr->ns) && xmlC14NIsVisible(ctx, attr, cur)) {
	    already_rendered = xmlExcC14NVisibleNsStackFind(ctx->ns_rendered, attr->ns, ctx);
	    xmlC14NVisibleNsStackAdd(ctx->ns_rendered, attr->ns, cur); 
	    if(!already_rendered && visible) {
		xmlListInsert(list, attr->ns); 
	    }
	    if(xmlStrlen(attr->ns->prefix) == 0) {
		has_empty_ns = 1;
	    }
	} else if(attr->ns == NULL) {
	    has_visibly_utilized_empty_ns = 1;
	}
    }

    /*
     * Process xmlns=""
     */
    if(visible && has_visibly_utilized_empty_ns && 
	    !has_empty_ns && !has_empty_ns_in_inclusive_list) {
        static xmlNs ns_default;

        memset(&ns_default, 0, sizeof(ns_default));
	
        already_rendered = xmlExcC14NVisibleNsStackFind(ctx->ns_rendered, &ns_default, ctx);
	if(!already_rendered) {
    	    xmlC14NPrintNamespaces(&ns_default, ctx);
	}
    } else if(visible && !has_empty_ns && has_empty_ns_in_inclusive_list) {
        static xmlNs ns_default;

        memset(&ns_default, 0, sizeof(ns_default));
        if(!xmlC14NVisibleNsStackFind(ctx->ns_rendered, &ns_default)) {
    	    xmlC14NPrintNamespaces(&ns_default, ctx);
	}
    }

    

    /* 
     * print out all elements from list 
     */
    xmlListWalk(list, (xmlListWalker) xmlC14NPrintNamespaces, (const void *) ctx);

    /* 
     * Cleanup
     */
    xmlListDelete(list);
    return (0);
}


/**
 * xmlC14NAttrsCompare:
 * @attr1:		the pointer tls o first attr
 * @attr2: 		the pointer to second attr
 *
 * Prints the given attribute to the output buffer from C14N context.
 *
 * Returns -1 if attr1 < attr2, 0 if attr1 == attr2 or 1 if attr1 > attr2.
 */
static int
xmlC14NAttrsCompare(xmlAttrPtr attr1, xmlAttrPtr attr2)
{
    int ret = 0;

    /*
     * Simple cases
     */
    if (attr1 == attr2)
        return (0);
    if (attr1 == NULL)
        return (-1);
    if (attr2 == NULL)
        return (1);
    if (attr1->ns == attr2->ns) {
        return (xmlStrcmp(attr1->name, attr2->name));
    }

    /* 
     * Attributes in the default namespace are first
     * because the default namespace is not applied to
     * unqualified attributes
     */
    if (attr1->ns == NULL)
        return (-1);
    if (attr2->ns == NULL)
        return (1);
    if (attr1->ns->prefix == NULL)
        return (-1);
    if (attr2->ns->prefix == NULL)
        return (1);

    ret = xmlStrcmp(attr1->ns->href, attr2->ns->href);
    if (ret == 0) {
        ret = xmlStrcmp(attr1->name, attr2->name);
    }
    return (ret);
}


/**
 * xmlC14NPrintAttrs:
 * @attr:		the pointer to attr
 * @ctx: 		the C14N context
 *
 * Prints out canonical attribute urrent node to the
 * buffer from C14N context as follows 
 *
 * Canonical XML v 1.0 (http://www.w3.org/TR/xml-c14n)
 *
 * Returns 1 on success or 0 on fail.
 */
static int
xmlC14NPrintAttrs(const xmlAttrPtr attr, xmlC14NCtxPtr ctx)
{
    xmlChar *value;
    xmlChar *buffer;

    if ((attr == NULL) || (ctx == NULL)) {
        xmlC14NErrParam("writing attributes");
        return (0);
    }

    xmlOutputBufferWriteString(ctx->buf, " ");
    if (attr->ns != NULL && xmlStrlen(attr->ns->prefix) > 0) {
        xmlOutputBufferWriteString(ctx->buf,
                                   (const char *) attr->ns->prefix);
        xmlOutputBufferWriteString(ctx->buf, ":");
    }
    xmlOutputBufferWriteString(ctx->buf, (const char *) attr->name);
    xmlOutputBufferWriteString(ctx->buf, "=\"");

    value = xmlNodeListGetString(attr->doc, attr->children, 1);
    /* todo: should we log an error if value==NULL ? */
    if (value != NULL) {
        buffer = xmlC11NNormalizeAttr(value);
        xmlFree(value);
        if (buffer != NULL) {
            xmlOutputBufferWriteString(ctx->buf, (const char *) buffer);
            xmlFree(buffer);
        } else {
            xmlC14NErrInternal("normalizing attributes axis");
            return (0);
        }
    }
    xmlOutputBufferWriteString(ctx->buf, "\"");
    return (1);
}

/**
 * xmlC14NProcessAttrsAxis:
 * @ctx: 		the C14N context
 * @cur:		the current node
 * @parent_visible:	the visibility of parent node
 *
 * Prints out canonical attribute axis of the current node to the
 * buffer from C14N context as follows 
 *
 * Canonical XML v 1.0 (http://www.w3.org/TR/xml-c14n)
 *
 * Attribute Axis 
 * In lexicographic order (ascending), process each node that 
 * is in the element's attribute axis and in the node-set.
 * 
 * The processing of an element node E MUST be modified slightly 
 * when an XPath node-set is given as input and the element's 
 * parent is omitted from the node-set.
 *
 *
 * Exclusive XML Canonicalization v 1.0 (http://www.w3.org/TR/xml-exc-c14n)
 *
 * Canonical XML applied to a document subset requires the search of the 
 * ancestor nodes of each orphan element node for attributes in the xml 
 * namespace, such as xml:lang and xml:space. These are copied into the 
 * element node except if a declaration of the same attribute is already 
 * in the attribute axis of the element (whether or not it is included in 
 * the document subset). This search and copying are omitted from the 
 * Exclusive XML Canonicalization method.
 *
 * Returns 0 on success or -1 on fail.
 */
static int
xmlC14NProcessAttrsAxis(xmlC14NCtxPtr ctx, xmlNodePtr cur, int parent_visible)
{
    xmlAttrPtr attr;
    xmlListPtr list;

    if ((ctx == NULL) || (cur == NULL) || (cur->type != XML_ELEMENT_NODE)) {
        xmlC14NErrParam("processing attributes axis");
        return (-1);
    }

    /*
     * Create a sorted list to store element attributes
     */
    list = xmlListCreate(NULL, (xmlListDataCompare) xmlC14NAttrsCompare);
    if (list == NULL) {
        xmlC14NErrInternal("creating attributes list");
        return (-1);
    }

    /* 
     * Add all visible attributes from current node. 
     */
    attr = cur->properties;
    while (attr != NULL) {
        /* check that attribute is visible */
        if (xmlC14NIsVisible(ctx, attr, cur)) {
            xmlListInsert(list, attr);
        }
        attr = attr->next;
    }

    /* 
     * include attributes in "xml" namespace defined in ancestors
     * (only for non-exclusive XML Canonicalization)
     */
    if (parent_visible && (!ctx->exclusive) && (cur->parent != NULL)
        && (!xmlC14NIsVisible(ctx, cur->parent, cur->parent->parent))) {
        /*
         * If XPath node-set is not specified then the parent is always 
         * visible!
         */
        cur = cur->parent;
        while (cur != NULL) {
            attr = cur->properties;
            while (attr != NULL) {
                if ((attr->ns != NULL)
                    && (xmlStrEqual(attr->ns->prefix, BAD_CAST "xml"))) {
                    if (xmlListSearch(list, attr) == NULL) {
                        xmlListInsert(list, attr);
                    }
                }
                attr = attr->next;
            }
            cur = cur->parent;
        }
    }

    /* 
     * print out all elements from list 
     */
    xmlListWalk(list, (xmlListWalker) xmlC14NPrintAttrs, (const void *) ctx);

    /* 
     * Cleanup
     */
    xmlListDelete(list);
    return (0);
}

/** 
 * xmlC14NCheckForRelativeNamespaces:
 * @ctx:		the C14N context
 * @cur:		the current element node
 *
 * Checks that current element node has no relative namespaces defined
 *
 * Returns 0 if the node has no relative namespaces or -1 otherwise.
 */
static int
xmlC14NCheckForRelativeNamespaces(xmlC14NCtxPtr ctx, xmlNodePtr cur)
{
    xmlNsPtr ns;

    if ((ctx == NULL) || (cur == NULL) || (cur->type != XML_ELEMENT_NODE)) {
        xmlC14NErrParam("checking for relative namespaces");
        return (-1);
    }

    ns = cur->nsDef;
    while (ns != NULL) {
        if (xmlStrlen(ns->href) > 0) {
            xmlURIPtr uri;

            uri = xmlParseURI((const char *) ns->href);
            if (uri == NULL) {
                xmlC14NErrInternal("parsing namespace uri");
                return (-1);
            }
            if (xmlStrlen((const xmlChar *) uri->scheme) == 0) {
                xmlC14NErrRelativeNamespace(uri->scheme);
                xmlFreeURI(uri);
                return (-1);
            }
            if ((xmlStrcasecmp((const xmlChar *) uri->scheme, BAD_CAST "urn") != 0)
                && (xmlStrcasecmp((const xmlChar *) uri->scheme, BAD_CAST "dav") !=0)
                && (xmlStrlen((const xmlChar *) uri->server) == 0)) {
                xmlC14NErrRelativeNamespace(uri->scheme);
                xmlFreeURI(uri);
                return (-1);
            }
            xmlFreeURI(uri);
        }
        ns = ns->next;
    }
    return (0);
}

/**
 * xmlC14NProcessElementNode:
 * @ctx: 		the pointer to C14N context object
 * @cur:		the node to process
 *  		
 * Canonical XML v 1.0 (http://www.w3.org/TR/xml-c14n)
 *
 * Element Nodes
 * If the element is not in the node-set, then the result is obtained 
 * by processing the namespace axis, then the attribute axis, then 
 * processing the child nodes of the element that are in the node-set 
 * (in document order). If the element is in the node-set, then the result 
 * is an open angle bracket (<), the element QName, the result of 
 * processing the namespace axis, the result of processing the attribute 
 * axis, a close angle bracket (>), the result of processing the child 
 * nodes of the element that are in the node-set (in document order), an 
 * open angle bracket, a forward slash (/), the element QName, and a close 
 * angle bracket.
 *
 * Returns non-negative value on success or negative value on fail
 */
static int
xmlC14NProcessElementNode(xmlC14NCtxPtr ctx, xmlNodePtr cur, int visible)
{
    int ret;
    xmlC14NVisibleNsStack state;
    int parent_is_doc = 0;

    if ((ctx == NULL) || (cur == NULL) || (cur->type != XML_ELEMENT_NODE)) {
        xmlC14NErrParam("processing element node");
        return (-1);
    }

    /* 
     * Check relative relative namespaces:
     * implementations of XML canonicalization MUST report an operation
     * failure on documents containing relative namespace URIs.
     */
    if (xmlC14NCheckForRelativeNamespaces(ctx, cur) < 0) {
        xmlC14NErrInternal("checking for relative namespaces");
        return (-1);
    }


    /* 
     * Save ns_rendered stack position
     */
    xmlC14NVisibleNsStackSave(ctx->ns_rendered, &state);

    if (visible) {	
        if (ctx->parent_is_doc) {
	    /* save this flag into the stack */
	    parent_is_doc = ctx->parent_is_doc;
	    ctx->parent_is_doc = 0;
            ctx->pos = XMLC14N_INSIDE_DOCUMENT_ELEMENT;
        }
        xmlOutputBufferWriteString(ctx->buf, "<");

        if ((cur->ns != NULL) && (xmlStrlen(cur->ns->prefix) > 0)) {
            xmlOutputBufferWriteString(ctx->buf,
                                       (const char *) cur->ns->prefix);
            xmlOutputBufferWriteString(ctx->buf, ":");
        }
        xmlOutputBufferWriteString(ctx->buf, (const char *) cur->name);