From 380d296bb2d369f8afa8a425201914d0726fcb3e Mon Sep 17 00:00:00 2001
From: Audric Ackermann <audric@loki.network>
Date: Mon, 23 Nov 2020 13:24:57 +1100
Subject: [PATCH] send session request if we get a message we cannot decode

This handle the case where we delete a contact from A, lets call him B
All message after that delete from B to A will be not decoded correctly.

The issue is that the record is existing, but there is no session in it.
The fix is that if we get a message and a record is found, but has not
session in it, we trigger a session request with that user
---
 libtextsecure/libsignal-protocol.js | 3 +++
 ts/receiver/contentMessage.ts       | 9 ++++++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/libtextsecure/libsignal-protocol.js b/libtextsecure/libsignal-protocol.js
index a9a47a80b..ee354ba58 100644
--- a/libtextsecure/libsignal-protocol.js
+++ b/libtextsecure/libsignal-protocol.js
@@ -36182,6 +36182,9 @@ SessionCipher.prototype = {
             if (!record) {
                 throw new Error("No record for device " + address);
             }
+            if (!record.getSessions() || record.getSessions().length === 0) {
+              throw new Error("No sessions for device " + address);
+            }
             var errors = [];
             return this.decryptWithSessionList(buffer, record.getSessions(), errors).then(function(result) {
                 return this.getRecord(address).then(function(record) {
diff --git a/ts/receiver/contentMessage.ts b/ts/receiver/contentMessage.ts
index 9e5431965..d849421c0 100644
--- a/ts/receiver/contentMessage.ts
+++ b/ts/receiver/contentMessage.ts
@@ -166,7 +166,6 @@ async function decryptUnidentifiedSender(
     const { sender: source } = error || {};
 
     if (source) {
-      // tslint:disable-next-line: no-shadowed-variable
       const blocked = await isBlocked(source.getName());
       if (blocked) {
         window.log.info(
@@ -176,6 +175,14 @@ async function decryptUnidentifiedSender(
         return null;
       }
 
+      if (error.message.startsWith('No sessions for device ')) {
+        // Receives a message from a specific device but we did not have a session with him.
+        // We trigger a session request.
+        await SessionProtocol.sendSessionRequestIfNeeded(
+          PubKey.cast(source.getName())
+        );
+      }
+
       // eslint-disable no-param-reassign
       envelope.source = source.getName();
       envelope.sourceDevice = source.getDeviceId();