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

@@ -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) {

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();