[Solved] Bug in (Mir)OTR: Unwanted answers with an empty message

[Testertime]

Solved: Bug occurs at other non-Miranda client, but was well hidden as it has only started with the new OTR plugin update for Miranda NG

Hello! Thanks to the developers who had updated MirOTR! I'm using the updated version since a few weeks now, and I found now a bug which is a little annoying. When I'm using the mobile Jabber client "Xabber" on Android and I'm writing with somebody after enabling the OTR session (who has Miranda NG and the plugin), in most cases I'm getting back an empty message instantly after I had sended my text message. Somehow it doesn't always happen, but mostly it does. Please look at the attached screenshot.

Steps to reproduce:

1. Download and install Xabber at an Android device (I had no luck testing it in a virtual machine with Android x86. Maybe BlueStacks works?)
2. Add your Jabber server account, for example use jit.si if you need one, start an OTR session with somebody and chat with him / her / yourself who is using the newest stable Miranda NG version with MirOTR.
3. When you chat with the other contact, you will see now an automatic-sended empty message from Miranda NG. If there isn't one, wait a few minutes before sending a message again. Usually then it does appear.

Luckily it is "only" an unnecessary empty extra message. There is no message content lost, like I thought before when I saw this unwanted behavior. This bug wasn't there before MirOTR was updated.

If somebody of you has the time, please find and hopefully kill this bug. Because it's still annoying though.

Thanks a lot in advance!

[White-Tiger]

did you try this with a Pidgin user yet?
There are some cases where OTR might modify a message to be empty... that's why the new MirOTR doesn't forward empty messages while the old MirOTR did exactly that... so some cases like you describe are actually prevented by the new MirOTR..

Since that filter is for user entered messages (such as when OTR prevents you to submit a message to an unencrypted session), it's not about automatic messages like you've described... automatic send messages are actually all protocol only... so it's possible that your client got some protocol problems or something...

Did you try those same steps with a Pidgin user instead of Miranda NG?
How about using a older protocol? Just try to start your OTR session with v2 from Miranda or your mobile client with a message that starts with "?OTRv2?"

[Testertime]

Did you try those same steps with a Pidgin user instead of Miranda NG?

I haven't. But I have done it now. After some testing it's the same effect here, that sometimes there is this empty message when I'm answering after a few minutes delay. I'm adding a screenshot again as a proof.

it's not about automatic messages like you've described... automatic send messages are actually all protocol only... so it's possible that your client got some protocol problems or something...

I guess I have explained it a little wrong These empty messages are looking like an automatic answer for me, because it's always happening after a short delay and if I'm writing something. I'm aware that it's not a "feature", more something unknown for me which causes this empty message. At first I thought it's maybe because of the message delivery receipts in Jabber, but I had tested it with Pidgin a few minutes ago, and it doesn't support message delivery receipts. So it's probably something with OTR.

[White-Tiger]

just to clarify, you say it's not a Miranda problem because it also happens with Pidgin? (can still be a Miranda problem, since OTR code is often based on Pidgin's)

Well... If I had time, I would maybe look into it Though that "if I had time" won't happen this month xD

What does your phone do when you're refreshing the OTR session from Miranda?

[Testertime]

just to clarify, you say it's not a Miranda problem because it also happens with Pidgin?

Right. I'm sorry if it was too confusing

(can still be a Miranda problem, since OTR code is often based on Pidgin's)

Interesting fact, good to know! So that's why it happens in Miranda and Pidgin. Now it's clear.

Well... If I had time, I would maybe look into it Though that "if I had time" won't happen this month xD

I'm thankful that you had already spend time to update MirOTR with a few other people, so it's fine Your engagement is still great!

What does your phone do when you're refreshing the OTR session from Miranda?

Have done it now, nothing special. It's refreshing fine. I have looked in Miranda NG, and it's OTR protocol version 2. So it looks like that Xabber doesn't support version 3 right now.

Still once again a screenshot for you if it's useful, especially because you can understand the text. There is always coming an empty message if I'm waiting at least 2 minutes between each message before I'm sending another message.

[White-Tiger]

Guess it's a bug in its client that just got visible through OTR v3 (but actually was a bug even before... just "luckily" didn't occur)
See: https://github.com/redsolution/xabber-android/issues/255 (known bug since very late 2013)

[Testertime]

Ooooh, interesting! I wish I saw that before. Now it's absolutely clear. Good to know!

but actually was a bug even before... just "luckily" didn't occur

Yes, that's why I thought it has to do something with the OTR update here for Miranda. So, great to see that the plugin is absolutely fine! Sorry if I had wasted your time on this matter, but now I know what's going on. I will edit the title.