Multidevice FR Fixes

[vincentbavitz]

Core Issues Fixed

FR Auto Accept From Secondary without Explicit from B

Issue

Three devices can get into a state where the primary device of one user remains in a deadlock where friend requests will never confirm.
The users can enter a state where one A1 is friends with B, and yet B never accepted ANY friend request from any of A's devices.

Desired Behaviour

When A2 messages B with a friend request, A1 should only auto-accept if B:

1. Explicitly accepts the FR from A2
2. Explicitly sends FR to A1
3. Sends message back to A2 or A1.

Reproduction

• B opens the friend request from A2 in the Contacts dropdown. B does NOT explicitly accept the friend request
  
• A2 syncs with A1.

Acceptance from B in Chat Yields Stalemate

Issue

Three devices can get into a stale mate where A1, being linked with A2, cannot establish a session with B after B has accepted a FR from A2 in chat.
When B accepts the FR from A2 in chat, (through clicking Accept, not through messaging), the conversation is marked as "Waiting for friend request approval" on B and A2, and is nonexistent for A1.

Desired Behaviour

When A2 messages B with a friend request, and B accepts,
A2 should first see FR approved, and sync with A1. A1 should Then

Reproduction

• A1 links with A2

• A2 sends FR to B

• B now sees from A2:

  isFriend: false
  isPendingFriendRequest: true
  hasReceivedFriendRequest: true
  hasSentFriendRequest: false
  activeAt: undefined
  lastMessage: {status: undefined, text: undefined}

• B accepts FR from A2 IN CHAT.
  This is a conversation with A1! Who has NOT sent a FR.
  
  Therefore B is trying to accept a non-existent FR.

Fixed.

Small Issues Fixed

FR From Secondary Showing in Conversations

Friend requests from secondary devices (A2) previously appeared in the Messages pane of the recipient (B). Fixed.

Can't Accept FR From Secondary in Contacts Dropdown

Friend requests from secondary devices (A2) were previously inactionable from the dropdown of the recipient (B). Accept / Decline had no effect as the actions pointed to the wrong conversation model.

Fixed.

Can't Accept FR From Secondary in Chat

The issue with accepting FR from A2 in the dialog, is that the FR accept is going to A1. We need to ensure that this message is only shown for the device who sent the FR.

[neuroscr]

Nitpick:

Really good documentation in the PR but reading the code there are few comments to see what changes map to what fix and/or comments WHY we want this new defined behavior. As you dove down into this mess, it really helps others to document what you learned in the code and also for yourself if you have to come back to the code again in 6+ months. If we had comments expressing the desired behavior you want, then it would be easier for us reviewers to confirm the code does what you want it to.

[vincentbavitz]

Nitpick:

Really good documentation in the PR but reading the code there are few comments to see what changes map to what fix and/or comments WHY we want this new defined behavior. As you dove down into this mess, it really helps others to document what you learned in the code and also for yourself if you have to come back to the code again in 6+ months. If we had comments expressing the desired behavior you want, then it would be easier for us reviewers to confirm the code does what you want it to.

Sure -- will update after lunch 👍

[Mikunj]

Looks good, had the similar comments to what Audric said.

[nielsandriesse]

This comment isn't true from a protocol perspective. Friend request acceptance happens on a per-device basis (because friend request status is device based and not user based). Also, declining a message doesn't send anything.

[nielsandriesse]

conversation.onAcceptFriendRequest() already loops through all devices associated with the contact, right? So invoking this for each of the contact's devices means you're going to send the friend request accepted message twice to each device 🤔

[Mikunj]

Uh it doesn't.

 async onAcceptFriendRequest(options = {}) {
      if (this.unlockTimer) {
        clearTimeout(this.unlockTimer);
      }
      if (this.hasReceivedFriendRequest()) {
        this.setFriendRequestStatus(FriendRequestStatusEnum.friends, options);

        await this.respondToAllFriendRequests({
          response: 'accepted',
          direction: 'incoming',
          status: ['pending', 'expired'],
        });
        window.libloki.api.sendBackgroundMessage(
          this.id,
          window.textsecure.OutgoingMessage.DebugMessageType
            .INCOMING_FR_ACCEPTED
        );
      }
    },

As seen from above it just sets its own friend request status and sends out a FR accept to the specific device.

[nielsandriesse]

Oh, I was looking at conversations.js → acceptFriendRequest(). I didn't realize there's a third method with this name :)