fst.getFirstArc(scratchArc);
        BytesRef matchOutput = null;

        int index = 0;
        while (start + index < src.length) {
            final int codePoint = Character.codePointAt(src, start + index, src.length);
            if (fst.findTargetArc(ignoreCase ? Character.toLowerCase(codePoint) : codePoint, scratchArc, scratchArc, fstReader) == null) {
                return matchOutput;
            }

                try {
                    char low = version.charAt(i + 1);
                    char[] both = {character, low};
                    c = Character.codePointAt(both, 0);
                    i++;
                } catch (IndexOutOfBoundsException ex) {
                    // high surrogate without low surrogate. Not a lot we can do here except treat it as a regular

        if (ComponentUtil.getFessConfig().isQueryHighlightBoundaryPositionDetect()) {
            int pos = escaped.indexOf(escapedHighlightPre);
            while (pos >= 0) {
                final int c = escaped.codePointAt(pos);
                if (Character.isISOControl(c) || highlightTerminalCharSet.contains(c)) {
                    break;
                }
                pos--;
            }

                final int length = spaceStr.length();
                spaceChars = new int[length];
                for (int i = 0; i < length; i++) {
                    spaceChars[i] = spaceStr.codePointAt(i);
                }
            }
            propMap.put(key, spaceChars);
        }
        return spaceChars;
    }

    String getCrawlerDocumentFullstopChars();