xmlNextChar(xmlParserCtxtPtr ctxt)
{
    if ((ctxt == NULL) || (ctxt->instate == XML_PARSER_EOF) ||
        (ctxt->input == NULL))
        return;

    if (ctxt->charset == XML_CHAR_ENCODING_UTF8) {
        if ((*ctxt->input->cur == 0) &&
            (xmlParserInputGrow(ctxt->input, INPUT_CHUNK) <= 0) &&
            (ctxt->instate != XML_PARSER_COMMENT)) {
            /*
             * If we are at the end of the current entity and
             * the context allows it, we pop consumed entities
             * automatically.
             * the auto closing should be blocked in other cases
             */
            xmlPopInput(ctxt);
        } else {
            const unsigned char *cur;
            unsigned char c;

            /*
             *   2.11 End-of-Line Handling
             *   the literal two-character sequence "#xD#xA" or a standalone
             *   literal #xD, an XML processor must pass to the application
             *   the single character #xA.
             */
            if (*(ctxt->input->cur) == '\n') {
                ctxt->input->line++; ctxt->input->col = 1;
            } else
                ctxt->input->col++;

            /*
             * We are supposed to handle UTF8, check it's valid
             * From rfc2044: encoding of the Unicode values on UTF-8:
             *
             * UCS-4 range (hex.)           UTF-8 octet sequence (binary)
             * 0000 0000-0000 007F   0xxxxxxx
             * 0000 0080-0000 07FF   110xxxxx 10xxxxxx
             * 0000 0800-0000 FFFF   1110xxxx 10xxxxxx 10xxxxxx
             *
             * Check for the 0x110000 limit too
             */
            cur = ctxt->input->cur;

            c = *cur;
            if (c & 0x80) {
	        if (c == 0xC0)
		    goto encoding_error;
                if (cur[1] == 0) {
                    xmlParserInputGrow(ctxt->input, INPUT_CHUNK);
                    cur = ctxt->input->cur;
                }
                if ((cur[1] & 0xc0) != 0x80)
                    goto encoding_error;
                if ((c & 0xe0) == 0xe0) {
                    unsigned int val;

                    if (cur[2] == 0) {
                        xmlParserInputGrow(ctxt->input, INPUT_CHUNK);
                        cur = ctxt->input->cur;
                    }
                    if ((cur[2] & 0xc0) != 0x80)
                        goto encoding_error;
                    if ((c & 0xf0) == 0xf0) {
                        if (cur[3] == 0) {
                            xmlParserInputGrow(ctxt->input, INPUT_CHUNK);
                            cur = ctxt->input->cur;
                        }
                        if (((c & 0xf8) != 0xf0) ||
                            ((cur[3] & 0xc0) != 0x80))
                            goto encoding_error;
                        /* 4-byte code */
                        ctxt->input->cur += 4;
                        val = (cur[0] & 0x7) << 18;
                        val |= (cur[1] & 0x3f) << 12;
                        val |= (cur[2] & 0x3f) << 6;
                        val |= cur[3] & 0x3f;
                    } else {
                        /* 3-byte code */
                        ctxt->input->cur += 3;
                        val = (cur[0] & 0xf) << 12;
                        val |= (cur[1] & 0x3f) << 6;
                        val |= cur[2] & 0x3f;
                    }
                    if (((val > 0xd7ff) && (val < 0xe000)) ||
                        ((val > 0xfffd) && (val < 0x10000)) ||
                        (val >= 0x110000)) {
			xmlErrEncodingInt(ctxt, XML_ERR_INVALID_CHAR,
					  "Char 0x%X out of allowed range\n",
					  val);
                    }
                } else
                    /* 2-byte code */
                    ctxt->input->cur += 2;
            } else
                /* 1-byte code */
                ctxt->input->cur++;

            ctxt->nbChars++;
            if (*ctxt->input->cur == 0)
                xmlParserInputGrow(ctxt->input, INPUT_CHUNK);
        }
    } else {
        /*
         * Assume it's a fixed length encoding (1) with
         * a compatible encoding for the ASCII set, since
         * XML constructs only use < 128 chars
         */

        if (*(ctxt->input->cur) == '\n') {
            ctxt->input->line++; ctxt->input->col = 1;
        } else
            ctxt->input->col++;
        ctxt->input->cur++;
        ctxt->nbChars++;
        if (*ctxt->input->cur == 0)
            xmlParserInputGrow(ctxt->input, INPUT_CHUNK);
    }
    if ((*ctxt->input->cur == '%') && (!ctxt->html))
        xmlParserHandlePEReference(ctxt);
    if ((*ctxt->input->cur == 0) &&
        (xmlParserInputGrow(ctxt->input, INPUT_CHUNK) <= 0))
        xmlPopInput(ctxt);
    return;
encoding_error:
    /*
     * If we detect an UTF8 error that probably mean that the
     * input encoding didn't get properly advertised in the
     * declaration header. Report the error and switch the encoding
     * to ISO-Latin-1 (if you don't like this policy, just declare the
     * encoding !)
     */
    if ((ctxt == NULL) || (ctxt->input == NULL) ||
        (ctxt->input->end - ctxt->input->cur < 4)) {
	__xmlErrEncoding(ctxt, XML_ERR_INVALID_CHAR,
		     "Input is not proper UTF-8, indicate encoding !\n",
		     NULL, NULL);
    } else {
        char buffer[150];

	snprintf(buffer, 149, "Bytes: 0x%02X 0x%02X 0x%02X 0x%02X\n",
			ctxt->input->cur[0], ctxt->input->cur[1],
			ctxt->input->cur[2], ctxt->input->cur[3]);
	__xmlErrEncoding(ctxt, XML_ERR_INVALID_CHAR,
		     "Input is not proper UTF-8, indicate encoding !\n%s",
		     BAD_CAST buffer, NULL);
    }
    ctxt->charset = XML_CHAR_ENCODING_8859_1;
    ctxt->input->cur++;
    return;
}
Unknown