From caf8bb39d860675c301d20ba8188bfa04f7de592 Mon Sep 17 00:00:00 2001
From: Alan Evans <alan@signal.org>
Date: Mon, 28 Sep 2020 11:48:09 -0300
Subject: [PATCH] Fix desktop sync with body-less messages.

---
 .../api/messages/SignalServiceDataMessage.java   | 16 +++++++++++++++-
 .../api/messages/SignalServiceGroupV2.java       |  4 ++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/libsignal/service/src/main/java/org/whispersystems/signalservice/api/messages/SignalServiceDataMessage.java b/libsignal/service/src/main/java/org/whispersystems/signalservice/api/messages/SignalServiceDataMessage.java
index 3458a5391..50a2961a8 100644
--- a/libsignal/service/src/main/java/org/whispersystems/signalservice/api/messages/SignalServiceDataMessage.java
+++ b/libsignal/service/src/main/java/org/whispersystems/signalservice/api/messages/SignalServiceDataMessage.java
@@ -159,7 +159,21 @@ public class SignalServiceDataMessage {
 
   public boolean isGroupV2Update() {
     return isGroupV2Message() &&
-           !body.isPresent();
+           group.get().getGroupV2().get().hasSignedGroupChange() &&
+           !hasRenderableContent();
+  }
+
+  /** Contains some user data that affects the conversation */
+  public boolean hasRenderableContent() {
+    return attachments.isPresent()   ||
+           body.isPresent()          ||
+           quote.isPresent()         ||
+           contacts.isPresent()      ||
+           previews.isPresent()      ||
+           mentions.isPresent()      ||
+           sticker.isPresent()       ||
+           reaction.isPresent()      ||
+           remoteDelete.isPresent();
   }
 
   public int getExpiresInSeconds() {
diff --git a/libsignal/service/src/main/java/org/whispersystems/signalservice/api/messages/SignalServiceGroupV2.java b/libsignal/service/src/main/java/org/whispersystems/signalservice/api/messages/SignalServiceGroupV2.java
index 1cefa2d3c..a4789a8d0 100644
--- a/libsignal/service/src/main/java/org/whispersystems/signalservice/api/messages/SignalServiceGroupV2.java
+++ b/libsignal/service/src/main/java/org/whispersystems/signalservice/api/messages/SignalServiceGroupV2.java
@@ -55,6 +55,10 @@ public final class SignalServiceGroupV2 {
     return signedGroupChange;
   }
 
+  public boolean hasSignedGroupChange() {
+    return signedGroupChange != null && signedGroupChange.length > 0;
+  }
+
   public static Builder newBuilder(GroupMasterKey masterKey) {
     return new Builder(masterKey);
   }