Identicon does not display in contact list for friends running older client

[anthonybilinski]

Brief Description

OS: Ubuntu 16.04
Commit hash: 42c4a74

Reproducible: Always

Steps to reproduce

1. Run client past identicon addition
2. Have contact come online running client before identicon addition

Observed Behavior

Before friend comes online, their avatar is shown as their identicon. Once they come online, in group list, they have the old default avatar. Selecting and de-selecting does not change it. Clicking "show details" on the friend shows the identicon, not the default avatar.

Expected Behavior

Identicon is showed in all places for the friend.

[tox-user]

@anthonybilinski is this issue still relevant in newer versions? I can't reproduce it.

[anthonybilinski]

Yes, I just reproduced it locally. Something that may interfere with reproducing is if the profile that you're opening on the pre-identicon version has ever been opened post-identicon, it will have generated an identicon and saved it locally, causing it to send that instead of an empty avatar when it connects to its friend. Since the issue it rooted in us deleting the avatar when we receive an empty avatar, this won't trigger it.

Creating a new profile on a qTox version pre-identicon and adding a post-identicon profile as a friend will cause this any time the old version comes online.

[anthonybilinski]

My (bad and abandoned) PR above points to the location in code where we delete the generated avatar for our friend when they come online and send us an empty avatar.

[tox-user]

Does a different client count as pre-identicon? My friend is running another client and I'm on qTox post identicon. I don't have this problem at all. If this issues is caused by an empty avatar it shouldn't matter which client sends it?

[anthonybilinski]

I just tried with uTox and couldn't reproduce. I don't see any log when the friend comes online, unlike what I see when a friend comes online in qTox or Antox:
[18:10:25.202 UTC] core/corefile.cpp:285 : Debug: "Received empty avatar request 43:65536", so I think uTox just doesn't send an empty avatar if it has no avatar.

I can reproduce with Antox and qTox.

[tox-user]

My friend was using Antox and I couldn't reproduce... I don't get any log message when they come online. Why does it even happen? This function is supposed to generate identicons for each empty avatar https://github.com/qTox/qTox/blob/master/src/persistence/profile.cpp#L395. Or is it not related?

[tox-user]

I might be using a different version of qTox.

[anthonybilinski]

To go over repro case more clearly:

1. Come online on new qTox client (after identicon addition), I'm using c274cec . This is friend 'A'.
   state from A's point of view: friend 'B' is offline, their avatar looks like an identicon, because like you pointed out, it's generated on load
2. Come online on old qTox client (before identicon addition), I'm using 68e0b46. This is friend 'B'
   state from B's point of view: B sees its own avatar as blank, it sees A's avatar as an identicon (because they're sharing config directories, and there's an avatar for A there)
   state from A's point of view: A sees old client as offline with an identicon avatar.
3. As soon as the two friends see each other come online, they send each other their avatars:
   3.1 A sends B an identicon as avatar, old client rejects it, since it's in cache. Nothing changes from B's point of view.
   3.2 B sends A an empty avatar (since no avatar is set), A sees that, logs [23:16:44.101 UTC] core/corefile.cpp:285 : Debug: "Received empty avatar request 43:65536", emits a signal that it received a request to delete an avatar, and un-sets the identicon that was loaded. A now sees B's avatar as a blank portrait (old style) instead of as the generated identicon.

I've you're not seeing the log that you received an empty avatar request, you definitely won't repro this issue. The empty avatar request is key as it is what causes the generated identicon to be deleted.