From cad9803d386d38376b22d731bc5d30a24c0f7987 Mon Sep 17 00:00:00 2001
From: Scott Nonnenberg <scott@signal.org>
Date: Thu, 10 Sep 2020 14:04:45 -0700
Subject: [PATCH] GroupsV2: Use both sent_at and received_at when processing
 changes

---
 js/models/messages.js |  3 ++-
 ts/groups.ts          | 13 ++++++++-----
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/js/models/messages.js b/js/models/messages.js
index 59a437daf7e..a456de47894 100644
--- a/js/models/messages.js
+++ b/js/models/messages.js
@@ -2463,7 +2463,8 @@
               conversation,
               groupChangeBase64: groupChange,
               newRevision: revision,
-              timestamp: message.get('received_at'),
+              receivedAt: message.get('received_at'),
+              sentAt: message.get('sent_at'),
             });
           } catch (error) {
             const errorText = error && error.stack ? error.stack : error;
diff --git a/ts/groups.ts b/ts/groups.ts
index 70b0ab2f492..89580114471 100644
--- a/ts/groups.ts
+++ b/ts/groups.ts
@@ -268,7 +268,8 @@ type MaybeUpdatePropsType = {
   conversation: ConversationModelType;
   groupChangeBase64?: string;
   newRevision?: number;
-  timestamp?: number;
+  receivedAt?: number;
+  sentAt?: number;
   dropInitialJoinMessage?: boolean;
 };
 
@@ -294,10 +295,11 @@ export async function waitThenMaybeUpdateGroup(options: MaybeUpdatePropsType) {
 
 export async function maybeUpdateGroup({
   conversation,
+  dropInitialJoinMessage,
   groupChangeBase64,
   newRevision,
-  timestamp,
-  dropInitialJoinMessage,
+  receivedAt,
+  sentAt,
 }: MaybeUpdatePropsType) {
   const logId = conversation.idForLogging();
 
@@ -321,8 +323,8 @@ export async function maybeUpdateGroup({
 
     // Ensure that all generated message are ordered properly. Before the provided timestamp
     //   so update messages appear before the initiating message, or after now().
-    let syntheticTimestamp = timestamp
-      ? timestamp - (groupChangeMessages.length + 1)
+    let syntheticTimestamp = receivedAt
+      ? receivedAt - (groupChangeMessages.length + 1)
       : Date.now();
     // Save all synthetic messages describing group changes
     const changeMessagesToSave = groupChangeMessages.map(changeMessage => {
@@ -333,6 +335,7 @@ export async function maybeUpdateGroup({
         ...changeMessage,
         conversationId: conversation.id,
         received_at: syntheticTimestamp,
+        sent_at: sentAt,
       };
     });