jline ConsoleReader discards the read line and returns null when the line reaches EOF

[chaoyu-tang]

In jline2 (jline-2.1.2.jar), the ConsoleReader discards the line content which has been read and returns null when the line reaches the end of the stream. See snippet of code in
class jline.console.ConsoleReader.java method:

public String readLine(String prompt, final Character mask) throws IOException:

            int c = pushBackChar.isEmpty() ? readCharacter() : pushBackChar.pop ();
            if (c == -1) {
                return null;
            }

---

and readCharacter():

public final int readCharacter() throws IOException {
    int c = reader.read();
    if (c >= 0) {
        Log.trace("Keystroke: ", c);
        // clear any echo characters
        if (terminal.isSupported()) {
            clearEcho(c);
        }
    }
    return c;
}

---

When EOF is reached in this line, the getCharacter() returns -1 and readLine returns null.