int doSelectionLineDown() { int line = content.getLineAtOffset(caretOffset);  if (line != caretLine) {   line = caretLine;
void doSelectionLineDown() { if (isSingleLine()) { return;
int doSelectionLineDown() {	int line = content.getLineAtOffset(caretOffset);		if (line != caretLine) {		// caret is at end of visual line/start of next visual line in 		// word wrap mode		line = caretLine;	}	// allow line down action only if receiver is not in single line mode.	// fixes 4820.	if (isSingleLine() == false && line < content.getLineCount() - 1) {		String lineText = content.getLine(line);		int offsetInLine = caretOffset - content.getOffsetAtLine(line);		int caretX = getXAtOffset(lineText, line, offsetInLine);				caretLine = ++line;		if (isBidi()) {			caretOffset = getBidiOffsetAtMouseLocation(caretX, line);		}		else {			caretOffset = getOffsetAtMouseLocation(caretX, line);		}			}	return line;}