Function htmlCheckEncoding

Externals/LibXML/HTMLparser.c:3290–3374

* htmlCheckEncoding: * @ctxt: an HTML parser context * @attvalue: the attribute value * * Checks an http-equiv attribute from a Meta tag to detect * the encoding * If a new encoding is detected the parser is switched to decode * it and pass UTF8 */

 * it and pass UTF8
 */
static void
htmlCheckEncoding(htmlParserCtxtPtr ctxt, const xmlChar *attvalue) {
    const xmlChar *encoding;

    if ((ctxt == NULL) || (attvalue == NULL))
	return;

    /* do not change encoding */	
    if (ctxt->input->encoding != NULL)
        return;

    encoding = xmlStrcasestr(attvalue, BAD_CAST"charset=");
    if (encoding != NULL) {
	encoding += 8;
    } else {
	encoding = xmlStrcasestr(attvalue, BAD_CAST"charset =");
	if (encoding != NULL)
	    encoding += 9;
    }
    if (encoding != NULL) {
	xmlCharEncoding enc;
	xmlCharEncodingHandlerPtr handler;

	while ((*encoding == ' ') || (*encoding == '\t')) encoding++;

	if (ctxt->input->encoding != NULL)
	    xmlFree((xmlChar *) ctxt->input->encoding);
	ctxt->input->encoding = xmlStrdup(encoding);

	enc = xmlParseCharEncoding((const char *) encoding);
	/*
	 * registered set of known encodings
	 */
	if (enc != XML_CHAR_ENCODING_ERROR) {
	    if (((enc == XML_CHAR_ENCODING_UTF16LE) || 
	         (enc == XML_CHAR_ENCODING_UTF16BE) ||
		 (enc == XML_CHAR_ENCODING_UCS4LE) ||
		 (enc == XML_CHAR_ENCODING_UCS4BE)) &&
		(ctxt->input->buf != NULL) &&
		(ctxt->input->buf->encoder == NULL)) {
		htmlParseErr(ctxt, XML_ERR_INVALID_ENCODING,
		             "htmlCheckEncoding: wrong encoding meta\n",
			     NULL, NULL);
	    } else {
		xmlSwitchEncoding(ctxt, enc);
	    }
	    ctxt->charset = XML_CHAR_ENCODING_UTF8;
	} else {
	    /*
	     * fallback for unknown encodings
	     */
	    handler = xmlFindCharEncodingHandler((const char *) encoding);
	    if (handler != NULL) {
		xmlSwitchToEncoding(ctxt, handler);
		ctxt->charset = XML_CHAR_ENCODING_UTF8;
	    } else {
		ctxt->errNo = XML_ERR_UNSUPPORTED_ENCODING;
	    }