Merge pull request #2231

    private static final int STATE_CR = 1;

    private static final int STATE_CRLF = 2;

    private int state = STATE_NORMAL;

    private int state = STATE_CRLF;

    public SmtpDataStuffing(OutputStream out) {

        super(out);

package com.fsck.k9.mail.filter;

import java.io.IOException;

import okio.Buffer;

import okio.ByteString;

import org.junit.Before;

import org.junit.Test;

import static junit.framework.Assert.assertEquals;

public class SmtpDataStuffingTest {

    private Buffer buffer;

    private SmtpDataStuffing smtpDataStuffing;

    @Before

    public void setUp() throws Exception {

        buffer = new Buffer();

        smtpDataStuffing = new SmtpDataStuffing(buffer.outputStream());

    }

    @Test

    public void dotAtStartOfLine() throws IOException {

        smtpDataStuffing.write(bytesFor("Hello dot\r\n."));

        assertEquals("Hello dot\r\n..", buffer.readUtf8());

    }

    @Test

    public void dotAtStartOfStream() throws IOException {

        smtpDataStuffing.write(bytesFor(".Hello dots"));

        assertEquals("..Hello dots", buffer.readUtf8());

    }

    @Test

    public void linesNotStartingWithDot() throws IOException {

        smtpDataStuffing.write(bytesFor("Hello\r\nworld\r\n"));

        assertEquals("Hello\r\nworld\r\n", buffer.readUtf8());

    }

    @Test

    public void dotsThatNeedStuffingMixedWithOnesThatDoNot() throws IOException {

        smtpDataStuffing.write(bytesFor("\r\n.Hello . dots.\r\n..\r\n.\r\n..."));

        assertEquals("\r\n..Hello . dots.\r\n...\r\n..\r\n....", buffer.readUtf8());

    }

    private byte[] bytesFor(String input) {

        return ByteString.encodeUtf8(input).toByteArray();

    }

}