Merge commit '6c75f0dc676d73c4cbcdca5a9cf05c6797a2ac0b' as 'libxml2'

1 files changed, 2238 insertions, 0 deletions

diff --git a/libxml2/c14n.c b/libxml2/c14n.c
new file mode 100644
index 0000000..ca77f92
--- /dev/null
+++ b/libxml2/c14n.c
@@ -0,0 +1,2238 @@
+/*
+ * "Canonical XML" implementation
+ * http://www.w3.org/TR/xml-c14n
+ *
+ * "Exclusive XML Canonicalization" implementation
+ * http://www.w3.org/TR/xml-exc-c14n
+ *
+ * See Copyright for the status of this software.
+ *
+ * Author: Aleksey Sanin <aleksey@aleksey.com>
+ */
+#define IN_LIBXML
+#include "libxml.h"
+#ifdef LIBXML_C14N_ENABLED
+#ifdef LIBXML_OUTPUT_ENABLED
+
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+#include <string.h>
+
+#include <libxml/tree.h>
+#include <libxml/parser.h>
+#include <libxml/uri.h>
+#include <libxml/xmlerror.h>
+#include <libxml/globals.h>
+#include <libxml/xpathInternals.h>
+#include <libxml/c14n.h>
+
+#include "buf.h"
+
+/************************************************************************
+ *									*
+ *		Some declaration better left private ATM		*
+ *									*
+ ************************************************************************/
+
+typedef enum {
+    XMLC14N_BEFORE_DOCUMENT_ELEMENT = 0,
+    XMLC14N_INSIDE_DOCUMENT_ELEMENT = 1,
+    XMLC14N_AFTER_DOCUMENT_ELEMENT = 2
+} xmlC14NPosition;
+
+typedef struct _xmlC14NVisibleNsStack {
+    int nsCurEnd;           /* number of nodes in the set */
+    int nsPrevStart;        /* the begginning of the stack for previous visible node */
+    int nsPrevEnd;          /* the end of the stack for previous visible node */
+    int nsMax;              /* size of the array as allocated */
+    xmlNsPtr	*nsTab;	    /* array of ns in no particular order */
+    xmlNodePtr	*nodeTab;   /* array of nodes in no particular order */
+} xmlC14NVisibleNsStack, *xmlC14NVisibleNsStackPtr;
+
+typedef struct _xmlC14NCtx {
+    /* input parameters */
+    xmlDocPtr doc;
+    xmlC14NIsVisibleCallback is_visible_callback;
+    void* user_data;
+    int with_comments;
+    xmlOutputBufferPtr buf;
+
+    /* position in the XML document */
+    xmlC14NPosition pos;
+    int parent_is_doc;
+    xmlC14NVisibleNsStackPtr ns_rendered;
+
+    /* C14N mode */
+    xmlC14NMode mode;
+
+    /* exclusive canonicalization */
+    xmlChar **inclusive_ns_prefixes;
+
+    /* error number */
+    int error;
+} xmlC14NCtx, *xmlC14NCtxPtr;
+
+static xmlC14NVisibleNsStackPtr	xmlC14NVisibleNsStackCreate	(void);
+static void     xmlC14NVisibleNsStackDestroy	(xmlC14NVisibleNsStackPtr cur);
+static void     xmlC14NVisibleNsStackAdd	    (xmlC14NVisibleNsStackPtr cur,
+                                                 xmlNsPtr ns,
+                                                 xmlNodePtr node);
+static void			xmlC14NVisibleNsStackSave	(xmlC14NVisibleNsStackPtr cur,
+								 xmlC14NVisibleNsStackPtr state);
+static void			xmlC14NVisibleNsStackRestore	(xmlC14NVisibleNsStackPtr cur,
+								 xmlC14NVisibleNsStackPtr state);
+static void			xmlC14NVisibleNsStackShift	(xmlC14NVisibleNsStackPtr cur);
+static int			xmlC14NVisibleNsStackFind	(xmlC14NVisibleNsStackPtr cur,
+								 xmlNsPtr ns);
+static int			xmlExcC14NVisibleNsStackFind	(xmlC14NVisibleNsStackPtr cur,
+								 xmlNsPtr ns,
+								 xmlC14NCtxPtr ctx);
+
+static int			xmlC14NIsNodeInNodeset		(xmlNodeSetPtr nodes,
+								 xmlNodePtr node,
+								 xmlNodePtr parent);
+
+
+
+static int xmlC14NProcessNode(xmlC14NCtxPtr ctx, xmlNodePtr cur);
+static int xmlC14NProcessNodeList(xmlC14NCtxPtr ctx, xmlNodePtr cur);
+typedef enum {
+    XMLC14N_NORMALIZE_ATTR = 0,
+    XMLC14N_NORMALIZE_COMMENT = 1,
+    XMLC14N_NORMALIZE_PI = 2,
+    XMLC14N_NORMALIZE_TEXT = 3
+} xmlC14NNormalizationMode;
+
+static xmlChar *xmlC11NNormalizeString(const xmlChar * input,
+                                       xmlC14NNormalizationMode mode);
+
+#define	xmlC11NNormalizeAttr( a ) \
+    xmlC11NNormalizeString((a), XMLC14N_NORMALIZE_ATTR)
+#define	xmlC11NNormalizeComment( a ) \
+    xmlC11NNormalizeString((a), XMLC14N_NORMALIZE_COMMENT)
+#define	xmlC11NNormalizePI( a )	\
+    xmlC11NNormalizeString((a), XMLC14N_NORMALIZE_PI)
+#define	xmlC11NNormalizeText( a ) \
+    xmlC11NNormalizeString((a), XMLC14N_NORMALIZE_TEXT)
+
+#define	xmlC14NIsVisible( ctx, node, parent ) \
+     (((ctx)->is_visible_callback != NULL) ? \
+	(ctx)->is_visible_callback((ctx)->user_data, \
+		(xmlNodePtr)(node), (xmlNodePtr)(parent)) : 1)
+
+#define	xmlC14NIsExclusive( ctx ) \
+    ( (ctx)->mode == XML_C14N_EXCLUSIVE_1_0 )
+
+/************************************************************************
+ *									*
+ *		Some factorized error routines				*
+ *									*
+ ************************************************************************/
+
+/**
+ * xmlC14NErrMemory:
+ * @extra:  extra informations
+ *
+ * Handle a redefinition of memory error
+ */
+static void
+xmlC14NErrMemory(const char *extra)
+{
+    __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
+		    XML_ERR_NO_MEMORY, XML_ERR_ERROR, NULL, 0, extra,
+		    NULL, NULL, 0, 0,
+		    "Memory allocation failed : %s\n", extra);
+}
+
+/**
+ * xmlC14NErrParam:
+ * @extra:  extra informations
+ *
+ * Handle a redefinition of param error
+ */
+static void
+xmlC14NErrParam(const char *extra)
+{
+    __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
+		    XML_ERR_INTERNAL_ERROR, XML_ERR_ERROR, NULL, 0, extra,
+		    NULL, NULL, 0, 0,
+		    "Invalid parameter : %s\n", extra);
+}
+
+/**
+ * xmlC14NErrInternal:
+ * @extra:  extra informations
+ *
+ * Handle a redefinition of internal error
+ */
+static void
+xmlC14NErrInternal(const char *extra)
+{
+    __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
+		    XML_ERR_INTERNAL_ERROR, XML_ERR_ERROR, NULL, 0, extra,
+		    NULL, NULL, 0, 0,
+		    "Internal error : %s\n", extra);
+}
+
+/**
+ * xmlC14NErrInvalidNode:
+ * @extra:  extra informations
+ *
+ * Handle a redefinition of invalid node error
+ */
+static void
+xmlC14NErrInvalidNode(const char *node_type, const char *extra)
+{
+    __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
+		    XML_C14N_INVALID_NODE, XML_ERR_ERROR, NULL, 0, extra,
+		    NULL, NULL, 0, 0,
+		    "Node %s is invalid here : %s\n", node_type, extra);
+}
+
+/**
+ * xmlC14NErrUnknownNode:
+ * @extra:  extra informations
+ *
+ * Handle a redefinition of unknown node error
+ */
+static void
+xmlC14NErrUnknownNode(int node_type, const char *extra)
+{
+    __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
+		    XML_C14N_UNKNOW_NODE, XML_ERR_ERROR, NULL, 0, extra,
+		    NULL, NULL, 0, 0,
+		    "Unknown node type %d found : %s\n", node_type, extra);
+}
+
+/**
+ * xmlC14NErrRelativeNamespace:
+ * @extra:  extra informations
+ *
+ * Handle a redefinition of relative namespace error
+ */
+static void
+xmlC14NErrRelativeNamespace(const char *ns_uri)
+{
+    __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
+		    XML_C14N_RELATIVE_NAMESPACE, XML_ERR_ERROR, NULL, 0, NULL,
+		    NULL, NULL, 0, 0,
+		    "Relative namespace UR is invalid here : %s\n", ns_uri);
+}
+
+
+
+/**
+ * xmlC14NErr:
+ * @ctxt:  a C14N evaluation context
+ * @node:  the context node
+ * @error:  the erorr code
+ * @msg:  the message
+ * @extra:  extra informations
+ *
+ * Handle a redefinition of attribute error
+ */
+static void
+xmlC14NErr(xmlC14NCtxPtr ctxt, xmlNodePtr node, int error,
+           const char * msg)
+{
+    if (ctxt != NULL)
+        ctxt->error = error;
+    __xmlRaiseError(NULL, NULL, NULL,
+		    ctxt, node, XML_FROM_C14N, error,
+		    XML_ERR_ERROR, NULL, 0,
+		    NULL, NULL, NULL, 0, 0, "%s", msg);
+}
+
+/************************************************************************
+ *									*
+ *		The implementation internals				*
+ *									*
+ ************************************************************************/
+#define XML_NAMESPACES_DEFAULT		16
+
+static int
+xmlC14NIsNodeInNodeset(xmlNodeSetPtr nodes, xmlNodePtr node, xmlNodePtr parent) {
+    if((nodes != NULL) && (node != NULL)) {
+	if(node->type != XML_NAMESPACE_DECL) {
+	    return(xmlXPathNodeSetContains(nodes, node));
+	} else {
+	    xmlNs ns;
+
+	    memcpy(&ns, node, sizeof(ns));
+
+	    /* this is a libxml hack! check xpath.c for details */
+	    if((parent != NULL) && (parent->type == XML_ATTRIBUTE_NODE)) {
+		ns.next = (xmlNsPtr)parent->parent;
+	    } else {
+		ns.next = (xmlNsPtr)parent;
+	    }
+
+	    /*
+	     * If the input is an XPath node-set, then the node-set must explicitly
+	     * contain every node to be rendered to the canonical form.
+	     */
+	    return(xmlXPathNodeSetContains(nodes, (xmlNodePtr)&ns));
+	}
+    }
+    return(1);
+}
+
+static xmlC14NVisibleNsStackPtr
+xmlC14NVisibleNsStackCreate(void) {
+    xmlC14NVisibleNsStackPtr ret;
+
+    ret = (xmlC14NVisibleNsStackPtr) xmlMalloc(sizeof(xmlC14NVisibleNsStack));
+    if (ret == NULL) {
+        xmlC14NErrMemory("creating namespaces stack");
+	return(NULL);
+    }
+    memset(ret, 0 , (size_t) sizeof(xmlC14NVisibleNsStack));
+    return(ret);
+}
+
+static void
+xmlC14NVisibleNsStackDestroy(xmlC14NVisibleNsStackPtr cur) {
+    if(cur == NULL) {
+        xmlC14NErrParam("destroying namespaces stack");
+        return;
+    }
+    if(cur->nsTab != NULL) {
+	memset(cur->nsTab, 0, cur->nsMax * sizeof(xmlNsPtr));
+	xmlFree(cur->nsTab);
+    }
+    if(cur->nodeTab != NULL) {
+	memset(cur->nodeTab, 0, cur->nsMax * sizeof(xmlNodePtr));
+	xmlFree(cur->nodeTab);
+    }
+    memset(cur, 0, sizeof(xmlC14NVisibleNsStack));
+    xmlFree(cur);
+
+}
+
+static void
+xmlC14NVisibleNsStackAdd(xmlC14NVisibleNsStackPtr cur, xmlNsPtr ns, xmlNodePtr node) {
+    if((cur == NULL) ||
+       ((cur->nsTab == NULL) && (cur->nodeTab != NULL)) ||
+       ((cur->nsTab != NULL) && (cur->nodeTab == NULL))) {
+        xmlC14NErrParam("adding namespace to stack");
+	return;
+    }
+
+    if ((cur->nsTab == NULL) && (cur->nodeTab == NULL)) {
+        cur->nsTab = (xmlNsPtr*) xmlMalloc(XML_NAMESPACES_DEFAULT * sizeof(xmlNsPtr));
+        cur->nodeTab = (xmlNodePtr*) xmlMalloc(XML_NAMESPACES_DEFAULT * sizeof(xmlNodePtr));
+	if ((cur->nsTab == NULL) || (cur->nodeTab == NULL)) {
+	    xmlC14NErrMemory("adding node to stack");
+	    return;
+	}
+	memset(cur->nsTab, 0 , XML_NAMESPACES_DEFAULT * sizeof(xmlNsPtr));
+	memset(cur->nodeTab, 0 , XML_NAMESPACES_DEFAULT * sizeof(xmlNodePtr));
+        cur->nsMax = XML_NAMESPACES_DEFAULT;
+    } else if(cur->nsMax == cur->nsCurEnd) {
+	void *tmp;
+	int tmpSize;
+
+	tmpSize = 2 * cur->nsMax;
+	tmp = xmlRealloc(cur->nsTab, tmpSize * sizeof(xmlNsPtr));
+	if (tmp == NULL) {
+	    xmlC14NErrMemory("adding node to stack");
+	    return;
+	}
+	cur->nsTab = (xmlNsPtr*)tmp;
+
+	tmp = xmlRealloc(cur->nodeTab, tmpSize * sizeof(xmlNodePtr));
+	if (tmp == NULL) {
+	    xmlC14NErrMemory("adding node to stack");
+	    return;
+	}
+	cur->nodeTab = (xmlNodePtr*)tmp;
+
+	cur->nsMax = tmpSize;
+    }
+    cur->nsTab[cur->nsCurEnd] = ns;
+    cur->nodeTab[cur->nsCurEnd] = node;
+
+    ++cur->nsCurEnd;
+}
+
+static void
+xmlC14NVisibleNsStackSave(xmlC14NVisibleNsStackPtr cur, xmlC14NVisibleNsStackPtr state) {
+    if((cur == NULL) || (state == NULL)) {
+        xmlC14NErrParam("saving namespaces stack");
+	return;
+    }
+
+    state->nsCurEnd = cur->nsCurEnd;
+    state->nsPrevStart = cur->nsPrevStart;
+    state->nsPrevEnd = cur->nsPrevEnd;
+}
+
+static void
+xmlC14NVisibleNsStackRestore(xmlC14NVisibleNsStackPtr cur, xmlC14NVisibleNsStackPtr state) {
+    if((cur == NULL) || (state == NULL)) {
+        xmlC14NErrParam("restoring namespaces stack");
+	return;
+    }
+    cur->nsCurEnd = state->nsCurEnd;
+    cur->nsPrevStart = state->nsPrevStart;
+    cur->nsPrevEnd = state->nsPrevEnd;
+}
+
+static void
+xmlC14NVisibleNsStackShift(xmlC14NVisibleNsStackPtr cur) {
+    if(cur == NULL) {
+        xmlC14NErrParam("shifting namespaces stack");
+	return;
+    }
+    cur->nsPrevStart = cur->nsPrevEnd;
+    cur->nsPrevEnd = cur->nsCurEnd;
+}
+
+static int
+xmlC14NStrEqual(const xmlChar *str1, const xmlChar *str2) {
+    if (str1 == str2) return(1);
+    if (str1 == NULL) return((*str2) == '\0');
+    if (str2 == NULL) return((*str1) == '\0');
+    do {
+	if (*str1++ != *str2) return(0);
+    } while (*str2++);
+    return(1);
+}
+
+/**
+ * xmlC14NVisibleNsStackFind:
+ * @ctx:		the C14N context
+ * @ns:			the namespace to check
+ *
+ * Checks whether the given namespace was already rendered or not
+ *
+ * Returns 1 if we already wrote this namespace or 0 otherwise
+ */
+static int
+xmlC14NVisibleNsStackFind(xmlC14NVisibleNsStackPtr cur, xmlNsPtr ns)
+{
+    int i;
+    const xmlChar *prefix;
+    const xmlChar *href;
+    int has_empty_ns;
+
+    if(cur == NULL) {
+        xmlC14NErrParam("searching namespaces stack (c14n)");
+        return (0);
+    }
+
+    /*
+     * if the default namespace xmlns="" is not defined yet then
+     * we do not want to print it out
+     */
+    prefix = ((ns == NULL) || (ns->prefix == NULL)) ? BAD_CAST "" : ns->prefix;
+    href = ((ns == NULL) || (ns->href == NULL)) ? BAD_CAST "" : ns->href;
+    has_empty_ns = (xmlC14NStrEqual(prefix, NULL) && xmlC14NStrEqual(href, NULL));
+
+    if (cur->nsTab != NULL) {
+	int start = (has_empty_ns) ? 0 : cur->nsPrevStart;
+        for (i = cur->nsCurEnd - 1; i >= start; --i) {
+            xmlNsPtr ns1 = cur->nsTab[i];
+
+	    if(xmlC14NStrEqual(prefix, (ns1 != NULL) ? ns1->prefix : NULL)) {
+		return(xmlC14NStrEqual(href, (ns1 != NULL) ? ns1->href : NULL));
+	    }
+        }
+    }
+    return(has_empty_ns);
+}
+
+static int
+xmlExcC14NVisibleNsStackFind(xmlC14NVisibleNsStackPtr cur, xmlNsPtr ns, xmlC14NCtxPtr ctx) {
+    int i;
+    const xmlChar *prefix;
+    const xmlChar *href;
+    int has_empty_ns;
+
+    if(cur == NULL) {
+        xmlC14NErrParam("searching namespaces stack (exc c14n)");
+        return (0);
+    }
+
+    /*
+     * if the default namespace xmlns="" is not defined yet then
+     * we do not want to print it out
+     */
+    prefix = ((ns == NULL) || (ns->prefix == NULL)) ? BAD_CAST "" : ns->prefix;
+    href = ((ns == NULL) || (ns->href == NULL)) ? BAD_CAST "" : ns->href;
+    has_empty_ns = (xmlC14NStrEqual(prefix, NULL) && xmlC14NStrEqual(href, NULL));
+
+    if (cur->nsTab != NULL) {
+	int start = 0;
+        for (i = cur->nsCurEnd - 1; i >= start; --i) {
+            xmlNsPtr ns1 = cur->nsTab[i];
+
+	    if(xmlC14NStrEqual(prefix, (ns1 != NULL) ? ns1->prefix : NULL)) {
+		if(xmlC14NStrEqual(href, (ns1 != NULL) ? ns1->href : NULL)) {
+		    return(xmlC14NIsVisible(ctx, ns1, cur->nodeTab[i]));
+		} else {
+		    return(0);
+		}
+	    }
+        }
+    }
+    return(has_empty_ns);
+}
+
+
+
+
+/**
+ * xmlC14NIsXmlNs:
+ * @ns:		the namespace to check
+ *
+ * Checks whether the given namespace is a default "xml:" namespace
+ * with href="http://www.w3.org/XML/1998/namespace"
+ *
+ * Returns 1 if the node is default or 0 otherwise
+ */
+
+/* todo: make it a define? */
+static int
+xmlC14NIsXmlNs(xmlNsPtr ns)
+{
+    return ((ns != NULL) &&
+            (xmlStrEqual(ns->prefix, BAD_CAST "xml")) &&
+            (xmlStrEqual(ns->href, XML_XML_NAMESPACE)));
+}
+
+
+/**
+ * xmlC14NNsCompare:
+ * @ns1:		the pointer to first namespace
+ * @ns2:		the pointer to second namespace
+ *
+ * Compares the namespaces by names (prefixes).
+ *
+ * Returns -1 if ns1 < ns2, 0 if ns1 == ns2 or 1 if ns1 > ns2.
+ */
+static int
+xmlC14NNsCompare(xmlNsPtr ns1, xmlNsPtr ns2)
+{
+    if (ns1 == ns2)
+        return (0);
+    if (ns1 == NULL)
+        return (-1);
+    if (ns2 == NULL)
+        return (1);
+
+    return (xmlStrcmp(ns1->prefix, ns2->prefix));
+}
+
+
+/**
+ * xmlC14NPrintNamespaces:
+ * @ns:			the pointer to namespace
+ * @ctx:		the C14N context
+ *
+ * Prints the given namespace to the output buffer from C14N context.
+ *
+ * Returns 1 on success or 0 on fail.
+ */
+static int
+xmlC14NPrintNamespaces(const xmlNsPtr ns, xmlC14NCtxPtr ctx)
+{
+
+    if ((ns == NULL) || (ctx == NULL)) {
+        xmlC14NErrParam("writing namespaces");
+        return 0;
+    }
+
+    if (ns->prefix != NULL) {
+        xmlOutputBufferWriteString(ctx->buf, " xmlns:");
+        xmlOutputBufferWriteString(ctx->buf, (const char *) ns->prefix);
+        xmlOutputBufferWriteString(ctx->buf, "=");
+    } else {
+        xmlOutputBufferWriteString(ctx->buf, " xmlns=");
+    }
+    if(ns->href != NULL) {
+	xmlBufWriteQuotedString(ctx->buf->buffer, ns->href);
+    } else {
+    	xmlOutputBufferWriteString(ctx->buf, "\"\"");
+    }
+    return (1);
+}
+
+/**
+ * xmlC14NProcessNamespacesAxis:
+ * @ctx:		the C14N context
+ * @node:		the current node
+ *
+ * Prints out canonical namespace 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)
+ *
+ * Namespace Axis
+ * Consider a list L containing only namespace nodes in the
+ * axis and in the node-set in lexicographic order (ascending). To begin
+ * processing L, if the first node is not the default namespace node (a node
+ * with no namespace URI and no local name), then generate a space followed
+ * by xmlns="" if and only if the following conditions are met:
+ *    - the element E that owns the axis is in the node-set
+ *    - The nearest ancestor element of E in the node-set has a default
+ *	    namespace node in the node-set (default namespace nodes always
+ *      have non-empty values in XPath)
+ * The latter condition eliminates unnecessary occurrences of xmlns="" in
+ * the canonical form since an element only receives an xmlns="" if its
+ * default namespace is empty and if it has an immediate parent in the
+ * canonical form that has a non-empty default namespace. To finish
+ * processing  L, simply process every namespace node in L, except omit
+ * namespace node with local name xml, which defines the xml prefix,
+ * if its string value is http://www.w3.org/XML/1998/namespace.
+ *
+ * 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
+xmlC14NProcessNamespacesAxis(xmlC14NCtxPtr ctx, xmlNodePtr cur, int visible)
+{
+    xmlNodePtr n;
+    xmlNsPtr ns, tmp;
+    xmlListPtr list;
+    int already_rendered;
+    int has_empty_ns = 0;
+
+    if ((ctx == NULL) || (cur == NULL) || (cur->type != XML_ELEMENT_NODE)) {
+        xmlC14NErrParam("processing namespaces axis (c14n)");
+        return (-1);
+    }
+
+    /*
+     * Create a sorted list to store element namespaces
+     */
+    list = xmlListCreate(NULL, (xmlListDataCompare) xmlC14NNsCompare);
+    if (list == NULL) {
+        xmlC14NErrInternal("creating namespaces list (c14n)");
+        return (-1);
+    }
+
+    /* check all namespaces */
+    for(n = cur; n != NULL; n = n->parent) {
+	for(ns = n->nsDef; ns != NULL; ns = ns->next) {
+	    tmp = xmlSearchNs(cur->doc, cur, ns->prefix);
+
+	    if((tmp == ns) && !xmlC14NIsXmlNs(ns) && xmlC14NIsVisible(ctx, ns, cur)) {
+		already_rendered = xmlC14NVisibleNsStackFind(ctx->ns_rendered, ns);
+		if(visible) {
+	    xmlC14NVisibleNsStackAdd(ctx->ns_rendered, ns, cur);
+		}
+		if(!already_rendered) {
+		    xmlListInsert(list, ns);
+		}
+		if(xmlStrlen(ns->prefix) == 0) {
+		    has_empty_ns = 1;
+		}
+	    }
+	}
+    }
+
+    /**
+     * if the first node is not the default namespace node (a node with no
+     * namespace URI and no local name), then generate a space followed by
+     * xmlns="" if and only if the following conditions are met:
+     *  - the element E that owns the axis is in the node-set
+     *  - the nearest ancestor element of E in the node-set has a default
+     *     namespace node in the node-set (default namespace nodes always
+     *     have non-empty values in XPath)
+     */
+    if(visible && !has_empty_ns) {
+        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);
+}
+
+
+/**
+ * xmlExcC14NProcessNamespacesAxis:
+ * @ctx:		the C14N context
+ * @node:		the current node
+ *
+ * Prints out exclusive canonical namespace axis of the current node to the
+ * buffer from C14N context as follows
+ *
+ * Exclusive XML Canonicalization
+ * http://www.w3.org/TR/xml-exc-c14n
+ *
+ * If the element node is in the XPath subset then output the node in
+ * accordance with Canonical XML except for namespace nodes which are
+ * rendered as follows:
+ *
+ * 1. Render each namespace node iff:
+ *    * it is visibly utilized by the immediate parent element or one of
+ *      its attributes, or is present in InclusiveNamespaces PrefixList, and
+ *    * its prefix and value do not appear in ns_rendered. ns_rendered is
+ *      obtained by popping the state stack in order to obtain a list of
+ *      prefixes and their values which have already been rendered by
+ *      an output ancestor of the namespace node's parent element.
+ * 2. Append the rendered namespace node to the list ns_rendered of namespace
+ * nodes rendered by output ancestors. Push ns_rendered on state stack and
+ * recurse.
+ * 3. After the recursion returns, pop thestate stack.
+ *
+ *
+ * Returns 0 on success or -1 on fail.
+ */
+static int
+xmlExcC14NProcessNamespacesAxis(xmlC14NCtxPtr ctx, xmlNodePtr cur, int visible)
+{
+    xmlNsPtr ns;
+    xmlListPtr list;
+    xmlAttrPtr attr;
+    int already_rendered;
+    int has_empty_ns = 0;
+    int has_visibly_utilized_empty_ns = 0;
+    int has_empty_ns_in_inclusive_list = 0;
+
+    if ((ctx == NULL) || (cur == NULL) || (cur->type != XML_ELEMENT_NODE)) {
+        xmlC14NErrParam("processing namespaces axis (exc c14n)");
+        return (-1);
+    }
+
+    if(!xmlC14NIsExclusive(ctx)) {
+        xmlC14NErrParam("processing namespaces axis (exc c14n)");
+        return (-1);
+
+    }
+
+    /*
+     * Create a sorted list to store element namespaces
+     */
+    list = xmlListCreate(NULL, (xmlListDataCompare) xmlC14NNsCompare);
+    if (list == NULL) {
+        xmlC14NErrInternal("creating namespaces list (exc c14n)");
+        return (-1);
+    }
+
+    /*
+     * process inclusive namespaces:
+     * All namespace nodes appearing on inclusive ns list are
+     * handled as provided in Canonical XML
+     */
+    if(ctx->inclusive_ns_prefixes != NULL) {
+	xmlChar *prefix;
+	int i;
+
+	for (i = 0; ctx->inclusive_ns_prefixes[i] != NULL; ++i) {
+	    prefix = ctx->inclusive_ns_prefixes[i];
+	    /*
+	     * Special values for namespace with empty prefix
+	     */
+            if (xmlStrEqual(prefix, BAD_CAST "#default")
+                || xmlStrEqual(prefix, BAD_CAST "")) {
+                prefix = NULL;
+		has_empty_ns_in_inclusive_list = 1;
+            }
+
+	    ns = xmlSearchNs(cur->doc, cur, prefix);
+	    if((ns != NULL) && !xmlC14NIsXmlNs(ns) && xmlC14NIsVisible(ctx, ns, cur)) {
+		already_rendered = xmlC14NVisibleNsStackFind(ctx->ns_rendered, ns);
+		if(visible) {
+		    xmlC14NVisibleNsStackAdd(ctx->ns_rendered, ns, cur);
+		}
+		if(!already_rendered) {
+		    xmlListInsert(list, ns);
+		}
+		if(xmlStrlen(ns->prefix) == 0) {
+		    has_empty_ns = 1;
+		}
+	    }
+	}
+    }
+
+    /* add node namespace */
+    if(cur->ns != NULL) {
+	ns = cur->ns;
+    } else {
+        ns = xmlSearchNs(cur->doc, cur, NULL);
+	has_visibly_utilized_empty_ns = 1;
+    }
+    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) && (xmlStrlen(attr->ns->prefix) == 0) && (xmlStrlen(attr->ns->href) == 0)) {
+	    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);
+}
+
+
+/**
+ * xmlC14NIsXmlAttr:
+ * @attr:		the attr to check
+ *
+ * Checks whether the given attribute is a default "xml:" namespace
+ * with href="http://www.w3.org/XML/1998/namespace"
+ *
+ * Returns 1 if the node is default or 0 otherwise
+ */
+
+/* todo: make it a define? */
+static int
+xmlC14NIsXmlAttr(xmlAttrPtr attr)
+{
+    return ((attr->ns != NULL) &&
+           (xmlC14NIsXmlNs(attr->ns) != 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(ctx->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);
+}
+
+/**
+ * xmlC14NFindHiddenParentAttr:
+ *
+ * Finds an attribute in a hidden parent node.
+ *
+ * Returns a pointer to the attribute node (if found) or NULL otherwise.
+ */
+static xmlAttrPtr
+xmlC14NFindHiddenParentAttr(xmlC14NCtxPtr ctx, xmlNodePtr cur, const xmlChar * name, const xmlChar * ns)
+{
+    xmlAttrPtr res;
+    while((cur != NULL) && (!xmlC14NIsVisible(ctx, cur, cur->parent))) {
+        res = xmlHasNsProp(cur, name, ns);
+        if(res != NULL) {
+            return res;
+        }
+
+        cur = cur->parent;
+    }
+
+    return NULL;
+}
+
+/**
+ * xmlC14NFixupBaseAttr:
+ *
+ * Fixes up the xml:base attribute
+ *
+ * Returns the newly created attribute or NULL
+ */
+static xmlAttrPtr
+xmlC14NFixupBaseAttr(xmlC14NCtxPtr ctx, xmlAttrPtr xml_base_attr)
+{
+    xmlChar * res = NULL;
+    xmlNodePtr cur;
+    xmlAttrPtr attr;
+    xmlChar * tmp_str;
+    xmlChar * tmp_str2;
+    int tmp_str_len;
+
+    if ((ctx == NULL) || (xml_base_attr == NULL) || (xml_base_attr->parent == NULL)) {
+        xmlC14NErrParam("processing xml:base attribute");
+        return (NULL);
+    }
+
+    /* start from current value */
+    res = xmlNodeListGetString(ctx->doc, xml_base_attr->children, 1);
+    if(res == NULL) {
+        xmlC14NErrInternal("processing xml:base attribute - can't get attr value");
+        return (NULL);
+    }
+
+    /* go up the stack until we find a node that we rendered already */
+    cur = xml_base_attr->parent->parent;
+    while((cur != NULL) && (!xmlC14NIsVisible(ctx, cur, cur->parent))) {
+        attr = xmlHasNsProp(cur, BAD_CAST "base", XML_XML_NAMESPACE);
+        if(attr != NULL) {
+            /* get attr value */
+            tmp_str = xmlNodeListGetString(ctx->doc, attr->children, 1);
+            if(tmp_str == NULL) {
+                xmlFree(res);
+
+                xmlC14NErrInternal("processing xml:base attribute - can't get attr value");
+                return (NULL);
+            }
+
+            /* we need to add '/' if our current base uri ends with '..' or '.'
+            to ensure that we are forced to go "up" all the time */
+            tmp_str_len = xmlStrlen(tmp_str);
+            if(tmp_str_len > 1 && tmp_str[tmp_str_len - 2] == '.') {
+                tmp_str2 = xmlStrcat(tmp_str, BAD_CAST "/");
+                if(tmp_str2 == NULL) {
+                    xmlFree(tmp_str);
+                    xmlFree(res);
+
+                    xmlC14NErrInternal("processing xml:base attribute - can't modify uri");
+                    return (NULL);
+                }
+
+                tmp_str = tmp_str2;
+            }
+
+            /* build uri */
+            tmp_str2 = xmlBuildURI(res, tmp_str);
+            if(tmp_str2 == NULL) {
+                xmlFree(tmp_str);
+                xmlFree(res);
+
+                xmlC14NErrInternal("processing xml:base attribute - can't construct uri");
+                return (NULL);
+            }
+
+            /* cleanup and set the new res */
+            xmlFree(tmp_str);
+            xmlFree(res);
+            res = tmp_str2;
+        }
+
+        /* next */
+        cur = cur->parent;
+    }
+
+    /* check if result uri is empty or not */
+    if((res == NULL) || xmlStrEqual(res, BAD_CAST "")) {
+        xmlFree(res);
+        return (NULL);
+    }
+
+    /* create and return the new attribute node */
+    attr = xmlNewNsProp(NULL, xml_base_attr->ns, BAD_CAST "base", res);
+    if(attr == NULL) {
+        xmlFree(res);
+
+        xmlC14NErrInternal("processing xml:base attribute - can't construct attribute");
+        return (NULL);
+    }
+
+    /* done */
+    xmlFree(res);
+    return (attr);
+}
+
+/**
+ * xmlC14NProcessAttrsAxis:
+ * @ctx:		the C14N context
+ * @cur:		the current node
+ * @parent_visible:	the visibility of parent node
+ * @all_parents_visible: the visibility of all parent nodes
+ *
+ * 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;
+    xmlAttrPtr attrs_to_delete = NULL;
+
+    /* special processing for 1.1 spec */
+    xmlAttrPtr xml_base_attr = NULL;
+    xmlAttrPtr xml_lang_attr = NULL;
+    xmlAttrPtr xml_space_attr = NULL;
+
+    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);
+    }
+
+    switch(ctx->mode) {
+    case XML_C14N_1_0:
+        /* 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. The method for processing
+         * the attribute axis of an element E in the node-set is enhanced. All element nodes along E's
+         * ancestor axis are examined for nearest occurrences of attributes in the xml namespace, such
+         * as xml:lang and xml:space (whether or not they are in the node-set). From this list of attributes,
+         * remove any that are in E's attribute axis (whether or not they are in the node-set). Then,
+         * lexicographically merge this attribute list with the nodes of E's attribute axis that are in
+         * the node-set. The result of visiting the attribute axis is computed by processing the attribute
+         * nodes in this merged attribute list.
+         */
+
+        /*
+         * 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;
+        }
+
+        /*
+         * Handle xml attributes
+         */
+        if (parent_visible && (cur->parent != NULL) &&
+            (!xmlC14NIsVisible(ctx, cur->parent, cur->parent->parent)))
+        {
+            xmlNodePtr tmp;
+
+            /*
+             * If XPath node-set is not specified then the parent is always
+             * visible!
+             */
+            tmp = cur->parent;
+            while (tmp != NULL) {
+                attr = tmp->properties;
+                while (attr != NULL) {
+                    if (xmlC14NIsXmlAttr(attr) != 0) {
+                        if (xmlListSearch(list, attr) == NULL) {
+                            xmlListInsert(list, attr);
+                        }
+                    }
+                    attr = attr->next;
+                }
+                tmp = tmp->parent;
+            }
+        }
+
+        /* done */
+        break;
+    case XML_C14N_EXCLUSIVE_1_0:
+        /* attributes in the XML namespace, such as xml:lang and xml:space
+         * are not imported into orphan nodes of the document subset
+         */
+
+        /*
+         * 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;
+        }
+
+        /* do nothing special for xml attributes */
+        break;
+    case XML_C14N_1_1:
+        /* The processing of an element node E MUST be modified slightly when an XPath node-set is
+         * given as input and some of the element's ancestors are omitted from the node-set.
+         *
+         * Simple inheritable attributes are attributes that have a value that requires at most a simple
+         * redeclaration. This redeclaration is done by supplying a new value in the child axis. The
+         * redeclaration of a simple inheritable attribute A contained in one of E's ancestors is done
+         * by supplying a value to an attribute Ae inside E with the same name. Simple inheritable attributes
+         * are xml:lang and xml:space.
+         *
+         * The method for processing the attribute axis of an element E in the node-set is hence enhanced.
+         * All element nodes along E's ancestor axis are examined for the nearest occurrences of simple
+         * inheritable attributes in the xml namespace, such as xml:lang and xml:space (whether or not they
+         * are in the node-set). From this list of attributes, any simple inheritable attributes that are
+         * already in E's attribute axis (whether or not they are in the node-set) are removed. Then,
+         * lexicographically merge this attribute list with the nodes of E's attribute axis that are in
+         * the node-set. The result of visiting the attribute axis is computed by processing the attribute
+         * nodes in this merged attribute list.
+         *
+         * The xml:id attribute is not a simple inheritable attribute and no processing of these attributes is
+         * performed.
+         *
+         * The xml:base attribute is not a simple inheritable attribute and requires special processing beyond
+         * a simple redeclaration.
+         *
+         * Attributes in the XML namespace other than xml:base, xml:id, xml:lang, and xml:space MUST be processed
+         * as ordinary attributes.
+         */
+
+        /*
+         * Add all visible attributes from current node.
+         */
+        attr = cur->properties;
+        while (attr != NULL) {
+            /* special processing for XML attribute kiks in only when we have invisible parents */
+            if ((!parent_visible) || (xmlC14NIsXmlAttr(attr) == 0)) {
+                /* check that attribute is visible */
+                if (xmlC14NIsVisible(ctx, attr, cur)) {
+                    xmlListInsert(list, attr);
+                }
+            } else {
+                int matched = 0;
+
+                /* check for simple inheritance attributes */
+                if((!matched) && (xml_lang_attr == NULL) && xmlStrEqual(attr->name, BAD_CAST "lang")) {
+                    xml_lang_attr = attr;
+                    matched = 1;
+                }
+                if((!matched) && (xml_space_attr == NULL) && xmlStrEqual(attr->name, BAD_CAST "space")) {
+                    xml_space_attr = attr;
+                    matched = 1;
+                }
+
+                /* check for base attr */
+                if((!matched) && (xml_base_attr == NULL) && xmlStrEqual(attr->name, BAD_CAST "base")) {
+                    xml_base_attr = attr;
+                    matched = 1;
+                }
+
+                /* otherwise, it is a normal attribute, so just check if it is visible */
+                if((!matched) && xmlC14NIsVisible(ctx, attr, cur)) {
+                    xmlListInsert(list, attr);
+                }
+            }
+
+            /* move to the next one */
+            attr = attr->next;
+        }
+
+        /* special processing for XML attribute kiks in only when we have invisible parents */
+        if ((parent_visible)) {
+
+            /* simple inheritance attributes - copy */
+            if(xml_lang_attr == NULL) {
+                xml_lang_attr = xmlC14NFindHiddenParentAttr(ctx, cur->parent, BAD_CAST "lang", XML_XML_NAMESPACE);
+            }
+            if(xml_lang_attr != NULL) {
+                xmlListInsert(list, xml_lang_attr);
+            }
+            if(xml_space_attr == NULL) {
+                xml_space_attr = xmlC14NFindHiddenParentAttr(ctx, cur->parent, BAD_CAST "space", XML_XML_NAMESPACE);
+            }
+            if(xml_space_attr != NULL) {
+                xmlListInsert(list, xml_space_attr);
+            }
+
+            /* base uri attribute - fix up */
+            if(xml_base_attr == NULL) {
+                /* if we don't have base uri attribute, check if we have a "hidden" one above */
+                xml_base_attr = xmlC14NFindHiddenParentAttr(ctx, cur->parent, BAD_CAST "base", XML_XML_NAMESPACE);
+            }
+            if(xml_base_attr != NULL) {
+                xml_base_attr = xmlC14NFixupBaseAttr(ctx, xml_base_attr);
+                if(xml_base_attr != NULL) {
+                    xmlListInsert(list, xml_base_attr);
+
+                    /* note that we MUST delete returned attr node ourselves! */
+                    xml_base_attr->next = attrs_to_delete;
+                    attrs_to_delete = xml_base_attr;
+                }
+            }
+        }
+
+        /* done */
+        break;
+    }
+
+    /*
+     * print out all elements from list
+     */
+    xmlListWalk(list, (xmlListWalker) xmlC14NPrintAttrs, (const void *) ctx);
+
+    /*
+     * Cleanup
+     */
+    xmlFreePropList(attrs_to_delete);
+    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
+ * @visible:    this node is visible
+ * @all_parents_visible: whether all the parents of this node are visible
+ *
+ * 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
+     */
+    memset(&state, 0, sizeof(state));
+    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);
+    }
+
+    if (!xmlC14NIsExclusive(ctx)) {
+        ret = xmlC14NProcessNamespacesAxis(ctx, cur, visible);
+    } else {
+        ret = xmlExcC14NProcessNamespacesAxis(ctx, cur, visible);
+    }
+    if (ret < 0) {
+        xmlC14NErrInternal("processing namespaces axis");
+        return (-1);
+    }
+    /* todo: shouldn't this go to "visible only"? */
+    if(visible) {
+	xmlC14NVisibleNsStackShift(ctx->ns_rendered);
+    }
+
+    ret = xmlC14NProcessAttrsAxis(ctx, cur, visible);
+    if (ret < 0) {
+	xmlC14NErrInternal("processing attributes axis");
+	return (-1);
+    }
+
+    if (visible) {
+        xmlOutputBufferWriteString(ctx->buf, ">");
+    }
+    if (cur->children != NULL) {
+        ret = xmlC14NProcessNodeList(ctx, cur->children);
+        if (ret < 0) {
+            xmlC14NErrInternal("processing childrens list");
+            return (-1);
+        }
+    }
+    if (visible) {
+        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);
+        xmlOutputBufferWriteString(ctx->buf, ">");
+        if (parent_is_doc) {
+	    /* restore this flag from the stack for next node */
+            ctx->parent_is_doc = parent_is_doc;
+	    ctx->pos = XMLC14N_AFTER_DOCUMENT_ELEMENT;
+        }
+    }
+
+    /*
+     * Restore ns_rendered stack position
+     */
+    xmlC14NVisibleNsStackRestore(ctx->ns_rendered, &state);
+    return (0);
+}
+
+/**
+ * xmlC14NProcessNode:
+ * @ctx:		the pointer to C14N context object
+ * @cur:		the node to process
+ *
+ * Processes the given node
+ *
+ * Returns non-negative value on success or negative value on fail
+ */
+static int
+xmlC14NProcessNode(xmlC14NCtxPtr ctx, xmlNodePtr cur)
+{
+    int ret = 0;
+    int visible;
+
+    if ((ctx == NULL) || (cur == NULL)) {
+        xmlC14NErrParam("processing node");
+        return (-1);
+    }
+
+    visible = xmlC14NIsVisible(ctx, cur, cur->parent);
+    switch (cur->type) {
+        case XML_ELEMENT_NODE:
+            ret = xmlC14NProcessElementNode(ctx, cur, visible);
+            break;
+        case XML_CDATA_SECTION_NODE:
+        case XML_TEXT_NODE:
+            /*
+             * Text Nodes
+             * the string value, except all ampersands are replaced
+             * by &amp;, all open angle brackets (<) are replaced by &lt;, all closing
+             * angle brackets (>) are replaced by &gt;, and all #xD characters are
+             * replaced by &#xD;.
+             */
+            /* cdata sections are processed as text nodes */
+            /* todo: verify that cdata sections are included in XPath nodes set */
+            if ((visible) && (cur->content != NULL)) {
+                xmlChar *buffer;
+
+                buffer = xmlC11NNormalizeText(cur->content);
+                if (buffer != NULL) {
+                    xmlOutputBufferWriteString(ctx->buf,
+                                               (const char *) buffer);
+                    xmlFree(buffer);
+                } else {
+                    xmlC14NErrInternal("normalizing text node");
+                    return (-1);
+                }
+            }
+            break;
+        case XML_PI_NODE:
+            /*
+             * Processing Instruction (PI) Nodes-
+             * The opening PI symbol (<?), the PI target name of the node,
+             * a leading space and the string value if it is not empty, and
+             * the closing PI symbol (?>). If the string value is empty,
+             * then the leading space is not added. Also, a trailing #xA is
+             * rendered after the closing PI symbol for PI children of the
+             * root node with a lesser document order than the document
+             * element, and a leading #xA is rendered before the opening PI
+             * symbol of PI children of the root node with a greater document
+             * order than the document element.
+             */
+            if (visible) {
+                if (ctx->pos == XMLC14N_AFTER_DOCUMENT_ELEMENT) {
+                    xmlOutputBufferWriteString(ctx->buf, "\x0A<?");
+                } else {
+                    xmlOutputBufferWriteString(ctx->buf, "<?");
+                }
+
+                xmlOutputBufferWriteString(ctx->buf,
+                                           (const char *) cur->name);
+                if ((cur->content != NULL) && (*(cur->content) != '\0')) {
+                    xmlChar *buffer;
+
+                    xmlOutputBufferWriteString(ctx->buf, " ");
+
+                    /* todo: do we need to normalize pi? */
+                    buffer = xmlC11NNormalizePI(cur->content);
+                    if (buffer != NULL) {
+                        xmlOutputBufferWriteString(ctx->buf,
+                                                   (const char *) buffer);
+                        xmlFree(buffer);
+                    } else {
+                        xmlC14NErrInternal("normalizing pi node");
+                        return (-1);
+                    }
+                }
+
+                if (ctx->pos == XMLC14N_BEFORE_DOCUMENT_ELEMENT) {
+                    xmlOutputBufferWriteString(ctx->buf, "?>\x0A");
+                } else {
+                    xmlOutputBufferWriteString(ctx->buf, "?>");
+                }
+            }
+            break;
+        case XML_COMMENT_NODE:
+            /*
+             * Comment Nodes
+             * Nothing if generating canonical XML without  comments. For
+             * canonical XML with comments, generate the opening comment
+             * symbol (<!--), the string value of the node, and the
+             * closing comment symbol (-->). Also, a trailing #xA is rendered
+             * after the closing comment symbol for comment children of the
+             * root node with a lesser document order than the document
+             * element, and a leading #xA is rendered before the opening
+             * comment symbol of comment children of the root node with a
+             * greater document order than the document element. (Comment
+             * children of the root node represent comments outside of the
+             * top-level document element and outside of the document type
+             * declaration).
+             */
+            if (visible && ctx->with_comments) {
+                if (ctx->pos == XMLC14N_AFTER_DOCUMENT_ELEMENT) {
+                    xmlOutputBufferWriteString(ctx->buf, "\x0A<!--");
+                } else {
+                    xmlOutputBufferWriteString(ctx->buf, "<!--");
+                }
+
+                if (cur->content != NULL) {
+                    xmlChar *buffer;
+
+                    /* todo: do we need to normalize comment? */
+                    buffer = xmlC11NNormalizeComment(cur->content);
+                    if (buffer != NULL) {
+                        xmlOutputBufferWriteString(ctx->buf,
+                                                   (const char *) buffer);
+                        xmlFree(buffer);
+                    } else {
+                        xmlC14NErrInternal("normalizing comment node");
+                        return (-1);
+                    }
+                }
+
+                if (ctx->pos == XMLC14N_BEFORE_DOCUMENT_ELEMENT) {
+                    xmlOutputBufferWriteString(ctx->buf, "-->\x0A");
+                } else {
+                    xmlOutputBufferWriteString(ctx->buf, "-->");
+                }
+            }
+            break;
+        case XML_DOCUMENT_NODE:
+        case XML_DOCUMENT_FRAG_NODE:   /* should be processed as document? */
+#ifdef LIBXML_DOCB_ENABLED
+        case XML_DOCB_DOCUMENT_NODE:   /* should be processed as document? */
+#endif
+#ifdef LIBXML_HTML_ENABLED
+        case XML_HTML_DOCUMENT_NODE:   /* should be processed as document? */
+#endif
+            if (cur->children != NULL) {
+                ctx->pos = XMLC14N_BEFORE_DOCUMENT_ELEMENT;
+                ctx->parent_is_doc = 1;
+                ret = xmlC14NProcessNodeList(ctx, cur->children);
+            }
+            break;
+
+        case XML_ATTRIBUTE_NODE:
+            xmlC14NErrInvalidNode("XML_ATTRIBUTE_NODE", "processing node");
+            return (-1);
+        case XML_NAMESPACE_DECL:
+            xmlC14NErrInvalidNode("XML_NAMESPACE_DECL", "processing node");
+            return (-1);
+        case XML_ENTITY_REF_NODE:
+            xmlC14NErrInvalidNode("XML_ENTITY_REF_NODE", "processing node");
+            return (-1);
+        case XML_ENTITY_NODE:
+            xmlC14NErrInvalidNode("XML_ENTITY_NODE", "processing node");
+            return (-1);
+
+        case XML_DOCUMENT_TYPE_NODE:
+        case XML_NOTATION_NODE:
+        case XML_DTD_NODE:
+        case XML_ELEMENT_DECL:
+        case XML_ATTRIBUTE_DECL:
+        case XML_ENTITY_DECL:
+#ifdef LIBXML_XINCLUDE_ENABLED
+        case XML_XINCLUDE_START:
+        case XML_XINCLUDE_END:
+#endif
+            /*
+             * should be ignored according to "W3C Canonical XML"
+             */
+            break;
+        default:
+            xmlC14NErrUnknownNode(cur->type, "processing node");
+            return (-1);
+    }
+
+    return (ret);
+}
+
+/**
+ * xmlC14NProcessNodeList:
+ * @ctx:		the pointer to C14N context object
+ * @cur:		the node to start from
+ *
+ * Processes all nodes in the row starting from cur.
+ *
+ * Returns non-negative value on success or negative value on fail
+ */
+static int
+xmlC14NProcessNodeList(xmlC14NCtxPtr ctx, xmlNodePtr cur)
+{
+    int ret;
+
+    if (ctx == NULL) {
+        xmlC14NErrParam("processing node list");
+        return (-1);
+    }
+
+    for (ret = 0; cur != NULL && ret >= 0; cur = cur->next) {
+        ret = xmlC14NProcessNode(ctx, cur);
+    }
+    return (ret);
+}
+
+
+/**
+ * xmlC14NFreeCtx:
+ * @ctx: the pointer to C14N context object
+ *
+ * Cleanups the C14N context object.
+ */
+
+static void
+xmlC14NFreeCtx(xmlC14NCtxPtr ctx)
+{
+    if (ctx == NULL) {
+        xmlC14NErrParam("freeing context");
+        return;
+    }
+
+    if (ctx->ns_rendered != NULL) {
+        xmlC14NVisibleNsStackDestroy(ctx->ns_rendered);
+    }
+    xmlFree(ctx);
+}
+
+/**
+ * xmlC14NNewCtx:
+ * @doc:		the XML document for canonization
+ * @is_visible_callback:the function to use to determine is node visible
+ *			or not
+ * @user_data:		the first parameter for @is_visible_callback function
+ *			(in most cases, it is nodes set)
+ * @mode:   the c14n mode (see @xmlC14NMode)
+ * @inclusive_ns_prefixe the list of inclusive namespace prefixes
+ *			ended with a NULL or NULL if there is no
+ *			inclusive namespaces (only for `
+ *			canonicalization)
+ * @with_comments:	include comments in the result (!=0) or not (==0)
+ * @buf:		the output buffer to store canonical XML; this
+ *			buffer MUST have encoder==NULL because C14N requires
+ *			UTF-8 output
+ *
+ * Creates new C14N context object to store C14N parameters.
+ *
+ * Returns pointer to newly created object (success) or NULL (fail)
+ */
+static xmlC14NCtxPtr
+xmlC14NNewCtx(xmlDocPtr doc,
+	      xmlC14NIsVisibleCallback is_visible_callback, void* user_data,
+              xmlC14NMode mode, xmlChar ** inclusive_ns_prefixes,
+              int with_comments, xmlOutputBufferPtr buf)
+{
+    xmlC14NCtxPtr ctx = NULL;
+
+    if ((doc == NULL) || (buf == NULL)) {
+        xmlC14NErrParam("creating new context");
+        return (NULL);
+    }
+
+    /*
+     *  Validate the encoding output buffer encoding
+     */
+    if (buf->encoder != NULL) {
+        xmlC14NErr(ctx, (xmlNodePtr) doc, XML_C14N_REQUIRES_UTF8,
+"xmlC14NNewCtx: output buffer encoder != NULL but C14N requires UTF8 output\n");
+        return (NULL);
+    }
+
+    /*
+     *  Validate the XML document encoding value, if provided.
+     */
+    if (doc->charset != XML_CHAR_ENCODING_UTF8) {
+        xmlC14NErr(ctx, (xmlNodePtr) doc, XML_C14N_REQUIRES_UTF8,
+		   "xmlC14NNewCtx: source document not in UTF8\n");
+        return (NULL);
+    }
+
+    /*
+     * Allocate a new xmlC14NCtxPtr and fill the fields.
+     */
+    ctx = (xmlC14NCtxPtr) xmlMalloc(sizeof(xmlC14NCtx));
+    if (ctx == NULL) {
+	xmlC14NErrMemory("creating context");
+        return (NULL);
+    }
+    memset(ctx, 0, sizeof(xmlC14NCtx));
+
+    /*
+     * initialize C14N context
+     */
+    ctx->doc = doc;
+    ctx->with_comments = with_comments;
+    ctx->is_visible_callback = is_visible_callback;
+    ctx->user_data = user_data;
+    ctx->buf = buf;
+    ctx->parent_is_doc = 1;
+    ctx->pos = XMLC14N_BEFORE_DOCUMENT_ELEMENT;
+    ctx->ns_rendered = xmlC14NVisibleNsStackCreate();
+
+    if(ctx->ns_rendered == NULL) {
+        xmlC14NErr(ctx, (xmlNodePtr) doc, XML_C14N_CREATE_STACK,
+		   "xmlC14NNewCtx: xmlC14NVisibleNsStackCreate failed\n");
+	xmlC14NFreeCtx(ctx);
+        return (NULL);
+    }
+
+    /*
+     * Set "mode" flag and remember list of incluseve prefixes
+     * for exclusive c14n
+     */
+    ctx->mode = mode;
+    if(xmlC14NIsExclusive(ctx)) {
+        ctx->inclusive_ns_prefixes = inclusive_ns_prefixes;
+    }
+    return (ctx);
+}
+
+/**
+ * xmlC14NExecute:
+ * @doc:		the XML document for canonization
+ * @is_visible_callback:the function to use to determine is node visible
+ *			or not
+ * @user_data:		the first parameter for @is_visible_callback function
+ *			(in most cases, it is nodes set)
+ * @mode:	the c14n mode (see @xmlC14NMode)
+ * @inclusive_ns_prefixes: the list of inclusive namespace prefixes
+ *			ended with a NULL or NULL if there is no
+ *			inclusive namespaces (only for exclusive
+ *			canonicalization, ignored otherwise)
+ * @with_comments:	include comments in the result (!=0) or not (==0)
+ * @buf:		the output buffer to store canonical XML; this
+ *			buffer MUST have encoder==NULL because C14N requires
+ *			UTF-8 output
+ *
+ * Dumps the canonized image of given XML document into the provided buffer.
+ * For details see "Canonical XML" (http://www.w3.org/TR/xml-c14n) or
+ * "Exclusive XML Canonicalization" (http://www.w3.org/TR/xml-exc-c14n)
+ *
+ * Returns non-negative value on success or a negative value on fail
+ */
+int
+xmlC14NExecute(xmlDocPtr doc, xmlC14NIsVisibleCallback is_visible_callback,
+	 void* user_data, int mode, xmlChar **inclusive_ns_prefixes,
+	 int with_comments, xmlOutputBufferPtr buf) {
+
+    xmlC14NCtxPtr ctx;
+    xmlC14NMode c14n_mode = XML_C14N_1_0;
+    int ret;
+
+    if ((buf == NULL) || (doc == NULL)) {
+        xmlC14NErrParam("executing c14n");
+        return (-1);
+    }
+
+    /* for backward compatibility, we have to have "mode" as "int"
+       and here we check that user gives valid value */
+    switch(mode) {
+    case XML_C14N_1_0:
+    case XML_C14N_EXCLUSIVE_1_0:
+    case XML_C14N_1_1:
+         c14n_mode = (xmlC14NMode)mode;
+         break;
+    default:
+        xmlC14NErrParam("invalid mode for executing c14n");
+        return (-1);
+    }
+
+    /*
+     *  Validate the encoding output buffer encoding
+     */
+    if (buf->encoder != NULL) {
+        xmlC14NErr(NULL, (xmlNodePtr) doc, XML_C14N_REQUIRES_UTF8,
+"xmlC14NExecute: output buffer encoder != NULL but C14N requires UTF8 output\n");
+        return (-1);
+    }
+
+    ctx = xmlC14NNewCtx(doc, is_visible_callback, user_data,
+	            c14n_mode, inclusive_ns_prefixes,
+                    with_comments, buf);
+    if (ctx == NULL) {
+        xmlC14NErr(NULL, (xmlNodePtr) doc, XML_C14N_CREATE_CTXT,
+		   "xmlC14NExecute: unable to create C14N context\n");
+        return (-1);
+    }
+
+
+
+    /*
+     * Root Node
+     * The root node is the parent of the top-level document element. The
+     * result of processing each of its child nodes that is in the node-set
+     * in document order. The root node does not generate a byte order mark,
+     * XML declaration, nor anything from within the document type
+     * declaration.
+     */
+    if (doc->children != NULL) {
+        ret = xmlC14NProcessNodeList(ctx, doc->children);
+        if (ret < 0) {
+            xmlC14NErrInternal("processing docs children list");
+            xmlC14NFreeCtx(ctx);
+            return (-1);
+        }
+    }
+
+    /*
+     * Flush buffer to get number of bytes written
+     */
+    ret = xmlOutputBufferFlush(buf);
+    if (ret < 0) {
+        xmlC14NErrInternal("flushing output buffer");
+        xmlC14NFreeCtx(ctx);
+        return (-1);
+    }
+
+    /*
+     * Cleanup
+     */
+    xmlC14NFreeCtx(ctx);
+    return (ret);
+}
+
+/**
+ * xmlC14NDocSaveTo:
+ * @doc:		the XML document for canonization
+ * @nodes:		the nodes set to be included in the canonized image
+ *		or NULL if all document nodes should be included
+ * @mode:		the c14n mode (see @xmlC14NMode)
+ * @inclusive_ns_prefixes: the list of inclusive namespace prefixes
+ *			ended with a NULL or NULL if there is no
+ *			inclusive namespaces (only for exclusive
+ *			canonicalization, ignored otherwise)
+ * @with_comments:	include comments in the result (!=0) or not (==0)
+ * @buf:		the output buffer to store canonical XML; this
+ *			buffer MUST have encoder==NULL because C14N requires
+ *			UTF-8 output
+ *
+ * Dumps the canonized image of given XML document into the provided buffer.
+ * For details see "Canonical XML" (http://www.w3.org/TR/xml-c14n) or
+ * "Exclusive XML Canonicalization" (http://www.w3.org/TR/xml-exc-c14n)
+ *
+ * Returns non-negative value on success or a negative value on fail
+ */
+int
+xmlC14NDocSaveTo(xmlDocPtr doc, xmlNodeSetPtr nodes,
+                 int mode, xmlChar ** inclusive_ns_prefixes,
+                 int with_comments, xmlOutputBufferPtr buf) {
+    return(xmlC14NExecute(doc,
+			(xmlC14NIsVisibleCallback)xmlC14NIsNodeInNodeset,
+			nodes,
+			mode,
+			inclusive_ns_prefixes,
+			with_comments,
+			buf));
+}
+
+
+/**
+ * xmlC14NDocDumpMemory:
+ * @doc:		the XML document for canonization
+ * @nodes:		the nodes set to be included in the canonized image
+ *		or NULL if all document nodes should be included
+ * @mode:		the c14n mode (see @xmlC14NMode)
+ * @inclusive_ns_prefixes: the list of inclusive namespace prefixes
+ *			ended with a NULL or NULL if there is no
+ *			inclusive namespaces (only for exclusive
+ *			canonicalization, ignored otherwise)
+ * @with_comments:	include comments in the result (!=0) or not (==0)
+ * @doc_txt_ptr:	the memory pointer for allocated canonical XML text;
+ *			the caller of this functions is responsible for calling
+ *			xmlFree() to free allocated memory
+ *
+ * Dumps the canonized image of given XML document into memory.
+ * For details see "Canonical XML" (http://www.w3.org/TR/xml-c14n) or
+ * "Exclusive XML Canonicalization" (http://www.w3.org/TR/xml-exc-c14n)
+ *
+ * Returns the number of bytes written on success or a negative value on fail
+ */
+int
+xmlC14NDocDumpMemory(xmlDocPtr doc, xmlNodeSetPtr nodes,
+                     int mode, xmlChar ** inclusive_ns_prefixes,
+                     int with_comments, xmlChar ** doc_txt_ptr)
+{
+    int ret;
+    xmlOutputBufferPtr buf;
+
+    if (doc_txt_ptr == NULL) {
+        xmlC14NErrParam("dumping doc to memory");
+        return (-1);
+    }
+
+    *doc_txt_ptr = NULL;
+
+    /*
+     * create memory buffer with UTF8 (default) encoding
+     */
+    buf = xmlAllocOutputBuffer(NULL);
+    if (buf == NULL) {
+        xmlC14NErrMemory("creating output buffer");
+        return (-1);
+    }
+
+    /*
+     * canonize document and write to buffer
+     */
+    ret = xmlC14NDocSaveTo(doc, nodes, mode, inclusive_ns_prefixes,
+                           with_comments, buf);
+    if (ret < 0) {
+        xmlC14NErrInternal("saving doc to output buffer");
+        (void) xmlOutputBufferClose(buf);
+        return (-1);
+    }
+
+    ret = xmlBufUse(buf->buffer);
+    if (ret > 0) {
+        *doc_txt_ptr = xmlStrndup(xmlBufContent(buf->buffer), ret);
+    }
+    (void) xmlOutputBufferClose(buf);
+
+    if ((*doc_txt_ptr == NULL) && (ret > 0)) {
+        xmlC14NErrMemory("coping canonicanized document");
+        return (-1);
+    }
+    return (ret);
+}
+
+/**
+ * xmlC14NDocSave:
+ * @doc:		the XML document for canonization
+ * @nodes:		the nodes set to be included in the canonized image
+ *		or NULL if all document nodes should be included
+ * @mode:		the c14n mode (see @xmlC14NMode)
+ * @inclusive_ns_prefixes: the list of inclusive namespace prefixes
+ *			ended with a NULL or NULL if there is no
+ *			inclusive namespaces (only for exclusive
+ *			canonicalization, ignored otherwise)
+ * @with_comments:	include comments in the result (!=0) or not (==0)
+ * @filename:		the filename to store canonical XML image
+ * @compression:	the compression level (zlib requred):
+ *				-1 - libxml default,
+ *				 0 - uncompressed,
+ *				>0 - compression level
+ *
+ * Dumps the canonized image of given XML document into the file.
+ * For details see "Canonical XML" (http://www.w3.org/TR/xml-c14n) or
+ * "Exclusive XML Canonicalization" (http://www.w3.org/TR/xml-exc-c14n)
+ *
+ * Returns the number of bytes written success or a negative value on fail
+ */
+int
+xmlC14NDocSave(xmlDocPtr doc, xmlNodeSetPtr nodes,
+               int mode, xmlChar ** inclusive_ns_prefixes,
+               int with_comments, const char *filename, int compression)
+{
+    xmlOutputBufferPtr buf;
+    int ret;
+
+    if (filename == NULL) {
+        xmlC14NErrParam("saving doc");
+        return (-1);
+    }
+#ifdef HAVE_ZLIB_H
+    if (compression < 0)
+        compression = xmlGetCompressMode();
+#endif
+
+    /*
+     * save the content to a temp buffer, use default UTF8 encoding.
+     */
+    buf = xmlOutputBufferCreateFilename(filename, NULL, compression);
+    if (buf == NULL) {
+        xmlC14NErrInternal("creating temporary filename");
+        return (-1);
+    }
+
+    /*
+     * canonize document and write to buffer
+     */
+    ret = xmlC14NDocSaveTo(doc, nodes, mode, inclusive_ns_prefixes,
+                           with_comments, buf);
+    if (ret < 0) {
+        xmlC14NErrInternal("cannicanize document to buffer");
+        (void) xmlOutputBufferClose(buf);
+        return (-1);
+    }
+
+    /*
+     * get the numbers of bytes written
+     */
+    ret = xmlOutputBufferClose(buf);
+    return (ret);
+}
+
+
+
+/*
+ * Macro used to grow the current buffer.
+ */
+#define growBufferReentrant() {						\
+    buffer_size *= 2;							\
+    buffer = (xmlChar *)						\
+		xmlRealloc(buffer, buffer_size * sizeof(xmlChar));	\
+    if (buffer == NULL) {						\
+	xmlC14NErrMemory("growing buffer");				\
+	return(NULL);							\
+    }									\
+}
+
+/**
+ * xmlC11NNormalizeString:
+ * @input:		the input string
+ * @mode:		the normalization mode (attribute, comment, PI or text)
+ *
+ * Converts a string to a canonical (normalized) format. The code is stolen
+ * from xmlEncodeEntitiesReentrant(). Added normalization of \x09, \x0a, \x0A
+ * and the @mode parameter
+ *
+ * Returns a normalized string (caller is responsible for calling xmlFree())
+ * or NULL if an error occurs
+ */
+static xmlChar *
+xmlC11NNormalizeString(const xmlChar * input,
+                       xmlC14NNormalizationMode mode)
+{
+    const xmlChar *cur = input;
+    xmlChar *buffer = NULL;
+    xmlChar *out = NULL;
+    int buffer_size = 0;
+
+    if (input == NULL)
+        return (NULL);
+
+    /*
+     * allocate an translation buffer.
+     */
+    buffer_size = 1000;
+    buffer = (xmlChar *) xmlMallocAtomic(buffer_size * sizeof(xmlChar));
+    if (buffer == NULL) {
+	xmlC14NErrMemory("allocating buffer");
+        return (NULL);
+    }
+    out = buffer;
+
+    while (*cur != '\0') {
+        if ((out - buffer) > (buffer_size - 10)) {
+            int indx = out - buffer;
+
+            growBufferReentrant();
+            out = &buffer[indx];
+        }
+
+        if ((*cur == '<') && ((mode == XMLC14N_NORMALIZE_ATTR) ||
+                              (mode == XMLC14N_NORMALIZE_TEXT))) {
+            *out++ = '&';
+            *out++ = 'l';
+            *out++ = 't';
+            *out++ = ';';
+        } else if ((*cur == '>') && (mode == XMLC14N_NORMALIZE_TEXT)) {
+            *out++ = '&';
+            *out++ = 'g';
+            *out++ = 't';
+            *out++ = ';';
+        } else if ((*cur == '&') && ((mode == XMLC14N_NORMALIZE_ATTR) ||
+                                     (mode == XMLC14N_NORMALIZE_TEXT))) {
+            *out++ = '&';
+            *out++ = 'a';
+            *out++ = 'm';
+            *out++ = 'p';
+            *out++ = ';';
+        } else if ((*cur == '"') && (mode == XMLC14N_NORMALIZE_ATTR)) {
+            *out++ = '&';
+            *out++ = 'q';
+            *out++ = 'u';
+            *out++ = 'o';
+            *out++ = 't';
+            *out++ = ';';
+        } else if ((*cur == '\x09') && (mode == XMLC14N_NORMALIZE_ATTR)) {
+            *out++ = '&';
+            *out++ = '#';
+            *out++ = 'x';
+            *out++ = '9';
+            *out++ = ';';
+        } else if ((*cur == '\x0A') && (mode == XMLC14N_NORMALIZE_ATTR)) {
+            *out++ = '&';
+            *out++ = '#';
+            *out++ = 'x';
+            *out++ = 'A';
+            *out++ = ';';
+        } else if ((*cur == '\x0D') && ((mode == XMLC14N_NORMALIZE_ATTR) ||
+                                        (mode == XMLC14N_NORMALIZE_TEXT) ||
+                                        (mode == XMLC14N_NORMALIZE_COMMENT) ||
+					(mode == XMLC14N_NORMALIZE_PI))) {
+            *out++ = '&';
+            *out++ = '#';
+            *out++ = 'x';
+            *out++ = 'D';
+            *out++ = ';';
+        } else {
+            /*
+             * Works because on UTF-8, all extended sequences cannot
+             * result in bytes in the ASCII range.
+             */
+            *out++ = *cur;
+        }
+        cur++;
+    }
+    *out = 0;
+    return (buffer);
+}
+#endif /* LIBXML_OUTPUT_ENABLED */
+#define bottom_c14n
+#include "elfgcchack.h"
+#endif /* LIBXML_C14N_ENABLED */