Gmail IMAP bug example testcase. If run, the output should include an invalid BODYSTRUCTURE string for message/rfc822 attachments

gmail-test.js

// GMAIL BUG:
// If a message has an message/rfc822 attachment then In-Reply-To value in the embedded envelope
// is forced to string even if the value was missing (the value is "NIL" instead of NIL)

// Usage: this is a node.js script, so you should have node installed (www.nodejs.org)
// replace USERNAME and PASSWORD values and run `node gmail-test.js`
// the output of this script is an IMAP log, see below for an example
// this script appends and removes a message with message/rfc822 attachments

var tls = require("tls");

var USERNAME = "[email protected]",
    PASSWORD = "password";

var message = 
    "MIME-Version: 1.0\r\n"+
    "From: [email protected]\r\n"+
    "To: [email protected]\r\n"+
    "Content-Type: multipart/mixed;\r\n"+
    "        boundary=\"----mailcomposer-?=_1-1328088797399\"\r\n"+
    "Message-Id: <testmessage-for-bug>;\r\n"+
    "\r\n"+
    "------mailcomposer-?=_1-1328088797399\r\n"+
    "Content-Type: message/rfc822\r\n"+
    "Content-Transfer-Encoding: 7bit\r\n"+
    "\r\n"+
    "MIME-Version: 1.0\r\n"+
    "From: [email protected]\r\n"+
    "To: [email protected]\r\n"+
    "In-Reply-To: <test1>\r\n"+
    "\r\n"+
    "Hello world!\r\n"+
    "------mailcomposer-?=_1-1328088797399\r\n"+
    "Content-Type: message/rfc822\r\n"+
    "Content-Transfer-Encoding: 7bit\r\n"+
    "\r\n"+
    "MIME-Version: 1.0\r\n"+
    "From: [email protected]\r\n"+
    "To: [email protected]\r\n"+
    "\r\n"+
    "Hello world!\r\n"+
    "------mailcomposer-?=_1-1328088797399\r\n"+
    "Content-Type: text/html; charset=utf-8\r\n"+
    "Content-Transfer-Encoding: quoted-printable\r\n"+
    "\r\n"+
    "<b>Hello world!</b>\r\n"+
    "------mailcomposer-?=_1-1328088797399--";

var commands = [
    "a1 LOGIN "+USERNAME+" "+PASSWORD,
    "a2 CAPABILITY",
    "a3 LIST \"\" \"*\"",
    "a4 LSUB \"\" \"*\"",
    "a5 SELECT INBOX",
    "a6 APPEND INBOX {" + (message.length) + "}",
    message,
    "a7 LOGOUT"
];

var socket = tls.connect(993, "imap.gmail.com", function(){
    socket.pipe(process.stdout);
    socket.on("data", function(data){
        var command, appendUID;

        if((appendUID = data.toString().match(/APPENDUID \d+ (\d+)/))){
            appendUID = appendUID[1];
            command = "af UID FETCH " + appendUID + " (ENVELOPE BODYSTRUCTURE)";
            commands.unshift("ad UID STORE " + appendUID + " +FLAGS (\\Deleted)");
            commands.unshift("ae EXPUNGE");
        }else{
            command = commands.shift()
        }

        if(command){
            socket.write(command + "\r\n");
        }
    });
});

/*

RESPONSE

ENVELOPE:
(
    "Mon, 2 Sep 2013 05:30:13 -0700 (PDT)"
    NIL
    ((NIL NIL "andris" "kreata.ee"))
    ((NIL NIL "andris" "kreata.ee"))
    ((NIL NIL "andris" "kreata.ee"))
    ((NIL NIL "andris" "tr.ee"))
    NIL
    NIL
    NIL  <-- NB! in-Reply-To not set, so this value is NIL
    "<-4730417346358914070@unknownmsgid>"
)

BODYSTRUCTURE:
(
    ("MESSAGE" "RFC822" NIL NIL NIL "7BIT" 105 
        (
            NIL NIL
            ((NIL NIL "andris" "kreata.ee"))
            ((NIL NIL "andris" "kreata.ee"))
            ((NIL NIL "andris" "kreata.ee"))
            ((NIL NIL "andris" "pangalink.net"))
            NIL
            NIL
            "<test1>" <--- NB! In-Reply-To value was <test1>, so this is OK
            NIL
        )
        ("TEXT" "PLAIN" NIL NIL NIL "7BIT" 12 0 NIL NIL NIL)
    5 NIL NIL NIL)
    ("MESSAGE" "RFC822" NIL NIL NIL "7BIT" 83 
        (
            NIL NIL 
            ((NIL NIL "andris" "kreata.ee"))
            ((NIL NIL "andris" "kreata.ee"))
            ((NIL NIL "andris" "kreata.ee"))
            ((NIL NIL "andris" "pangalink.net"))
            NIL
            NIL
            "NIL" <-- NB! Here is a bug! Should be NIL (null value) instead of "NIL" (string value)
            NIL
        )
        ("TEXT" "PLAIN" NIL NIL NIL "7BIT" 12 0 NIL NIL NIL)
    4 NIL NIL NIL
    )
    ("TEXT" "HTML" ("CHARSET" "utf-8") NIL NIL "QUOTED-PRINTABLE" 19 0 NIL NIL NIL)
    "MIXED"
    ("BOUNDARY" "----mailcomposer-?=_1-1328088797399")
    NIL
    NIL
)
*/