xmlParseChunk(xmlParserCtxtPtr ctxt, const char *chunk, int size,
              int terminate) {
    int end_in_lf = 0;
    int remain = 0;
    size_t old_avail = 0;
    size_t avail = 0;

    if (ctxt == NULL)
        return(XML_ERR_INTERNAL_ERROR);
    if ((ctxt->errNo != XML_ERR_OK) && (ctxt->disableSAX == 1))
        return(ctxt->errNo);
    if (ctxt->instate == XML_PARSER_EOF)
        return(-1);
    if (ctxt->instate == XML_PARSER_START)
        xmlDetectSAX2(ctxt);
    if ((size > 0) && (chunk != NULL) && (!terminate) &&
        (chunk[size - 1] == '\r')) {
	end_in_lf = 1;
	size--;
    }

xmldecl_done:

    if ((size > 0) && (chunk != NULL) && (ctxt->input != NULL) &&
        (ctxt->input->buf != NULL) && (ctxt->instate != XML_PARSER_EOF))  {
	size_t base = xmlBufGetInputBase(ctxt->input->buf->buffer, ctxt->input);
	size_t cur = ctxt->input->cur - ctxt->input->base;
	int res;

        old_avail = xmlBufUse(ctxt->input->buf->buffer);
        /*
         * Specific handling if we autodetected an encoding, we should not
         * push more than the first line ... which depend on the encoding
         * And only push the rest once the final encoding was detected
         */
        if ((ctxt->instate == XML_PARSER_START) && (ctxt->input != NULL) &&
            (ctxt->input->buf != NULL) && (ctxt->input->buf->encoder != NULL)) {
            unsigned int len = 45;

            if ((xmlStrcasestr(BAD_CAST ctxt->input->buf->encoder->name,
                               BAD_CAST "UTF-16")) ||
                (xmlStrcasestr(BAD_CAST ctxt->input->buf->encoder->name,
                               BAD_CAST "UTF16")))
                len = 90;
            else if ((xmlStrcasestr(BAD_CAST ctxt->input->buf->encoder->name,
                                    BAD_CAST "UCS-4")) ||
                     (xmlStrcasestr(BAD_CAST ctxt->input->buf->encoder->name,
                                    BAD_CAST "UCS4")))
                len = 180;

            if (ctxt->input->buf->rawconsumed < len)
                len -= ctxt->input->buf->rawconsumed;

            /*
             * Change size for reading the initial declaration only
             * if size is greater than len. Otherwise, memmove in xmlBufferAdd
             * will blindly copy extra bytes from memory.
             */
            if ((unsigned int) size > len) {
                remain = size - len;
                size = len;
            } else {
                remain = 0;
            }
        }
	res = xmlParserInputBufferPush(ctxt->input->buf, size, chunk);
        xmlBufSetInputBaseCur(ctxt->input->buf->buffer, ctxt->input, base, cur);
	if (res < 0) {
	    ctxt->errNo = XML_PARSER_EOF;
	    xmlHaltParser(ctxt);
	    return (XML_PARSER_EOF);
	}
#ifdef DEBUG_PUSH
	xmlGenericError(xmlGenericErrorContext, "PP: pushed %d\n", size);
#endif

    } else if (ctxt->instate != XML_PARSER_EOF) {
	if ((ctxt->input != NULL) && ctxt->input->buf != NULL) {
	    xmlParserInputBufferPtr in = ctxt->input->buf;
	    if ((in->encoder != NULL) && (in->buffer != NULL) &&
		    (in->raw != NULL)) {
		int nbchars;
		size_t base = xmlBufGetInputBase(in->buffer, ctxt->input);
		size_t current = ctxt->input->cur - ctxt->input->base;

		nbchars = xmlCharEncInput(in, terminate);
		xmlBufSetInputBaseCur(in->buffer, ctxt->input, base, current);
		if (nbchars < 0) {
		    /* TODO 2.6.0 */
		    xmlGenericError(xmlGenericErrorContext,
				    "xmlParseChunk: encoder error\n");
                    xmlHaltParser(ctxt);
		    return(XML_ERR_INVALID_ENCODING);
		}
	    }
	}
    }
    if (remain != 0) {
        xmlParseTryOrFinish(ctxt, 0);
    } else {
        if ((ctxt->input != NULL) && (ctxt->input->buf != NULL))
            avail = xmlBufUse(ctxt->input->buf->buffer);
        /*
         * Depending on the current state it may not be such
         * a good idea to try parsing if there is nothing in the chunk
         * which would be worth doing a parser state transition and we
         * need to wait for more data
         */
        if ((terminate) || (avail > XML_MAX_TEXT_LENGTH) ||
            (old_avail == 0) || (avail == 0) ||
            (xmlParseCheckTransition(ctxt,
                       (const char *)&ctxt->input->base[old_avail],
                                     avail - old_avail)))
            xmlParseTryOrFinish(ctxt, terminate);
    }
    if (ctxt->instate == XML_PARSER_EOF)
        return(ctxt->errNo);

    if ((ctxt->input != NULL) &&
         (((ctxt->input->end - ctxt->input->cur) > XML_MAX_LOOKUP_LIMIT) ||
         ((ctxt->input->cur - ctxt->input->base) > XML_MAX_LOOKUP_LIMIT)) &&
        ((ctxt->options & XML_PARSE_HUGE) == 0)) {
        xmlFatalErr(ctxt, XML_ERR_INTERNAL_ERROR, "Huge input lookup");
        xmlHaltParser(ctxt);
    }
    if ((ctxt->errNo != XML_ERR_OK) && (ctxt->disableSAX == 1))
        return(ctxt->errNo);

    if (remain != 0) {
        chunk += size;
        size = remain;
        remain = 0;
        goto xmldecl_done;
    }
    if ((end_in_lf == 1) && (ctxt->input != NULL) &&
        (ctxt->input->buf != NULL)) {
	size_t base = xmlBufGetInputBase(ctxt->input->buf->buffer,
					 ctxt->input);
	size_t current = ctxt->input->cur - ctxt->input->base;

	xmlParserInputBufferPush(ctxt->input->buf, 1, "\r");

	xmlBufSetInputBaseCur(ctxt->input->buf->buffer, ctxt->input,
			      base, current);
    }
    if (terminate) {
	/*
	 * Check for termination
	 */
	int cur_avail = 0;

	if (ctxt->input != NULL) {
	    if (ctxt->input->buf == NULL)
		cur_avail = ctxt->input->length -
			    (ctxt->input->cur - ctxt->input->base);
	    else
		cur_avail = xmlBufUse(ctxt->input->buf->buffer) -
			              (ctxt->input->cur - ctxt->input->base);
	}

	if ((ctxt->instate != XML_PARSER_EOF) &&
	    (ctxt->instate != XML_PARSER_EPILOG)) {
	    xmlFatalErr(ctxt, XML_ERR_DOCUMENT_END, NULL);
	}
	if ((ctxt->instate == XML_PARSER_EPILOG) && (cur_avail > 0)) {
	    xmlFatalErr(ctxt, XML_ERR_DOCUMENT_END, NULL);
	}
	if (ctxt->instate != XML_PARSER_EOF) {
	    if ((ctxt->sax) && (ctxt->sax->endDocument != NULL))
		ctxt->sax->endDocument(ctxt->userData);
	}
	ctxt->instate = XML_PARSER_EOF;
    }
    if (ctxt->wellFormed == 0)
	return((xmlParserErrors) ctxt->errNo);
    else
        return(0);
}