From c54d3abe473a1313d27d6de4812604e9bb63e3ba Mon Sep 17 00:00:00 2001
From: Jon Chambers <jon@signal.org>
Date: Thu, 24 Sep 2020 18:56:29 -0400
Subject: [PATCH] Check for the second-gen GV2 capability when linking devices.

---
 .../textsecuregcm/controllers/DeviceController.java           | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/controllers/DeviceController.java b/service/src/main/java/org/whispersystems/textsecuregcm/controllers/DeviceController.java
index 29f9b302f..3e2f06736 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/controllers/DeviceController.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/controllers/DeviceController.java
@@ -242,6 +242,8 @@ public class DeviceController {
   }
 
   private boolean isCapabilityDowngrade(Account account, DeviceCapabilities capabilities) {
-    return (!capabilities.isGv2() && account.isGroupsV2Supported());
+    // Only iOS and desktop clients can be linked devices right now, and both require the second-gen GV2 capability to
+    // support GV2.
+    return (!capabilities.isGv2_2() && account.isGroupsV2Supported());
   }
 }