@Override
	protected String readLineInternal() throws IOException {
		if (skippingDone == false) {
			skippingDone = true;
			do {
				final String s = readLine();
				if (s == null) {
					return null;
				}
				Matcher m = endifPattern.matcher(s);
				if (m.find()) {
					return null;
				}
				m = elsePattern.matcher(s);
				if (m.find()) {
					break;
				}
			} while (true);
		}

		final String s = super.readLineInternal();
		if (s == null) {
			return null;
		}
		final Matcher m = endifPattern.matcher(s);
		if (m.find()) {
			return null;
		}
		return s;

	}