From af6a7c103c83b1b0cf3e81885fe145d75a2324f3 Mon Sep 17 00:00:00 2001
From: Matthew Chen <charlesmchen@gmail.com>
Date: Fri, 10 Nov 2017 14:08:52 -0500
Subject: [PATCH] Add a comment.

---
 .../ConversationView/ConversationViewController.m               | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Signal/src/ViewControllers/ConversationView/ConversationViewController.m b/Signal/src/ViewControllers/ConversationView/ConversationViewController.m
index a4fde938c..3c09b7fbb 100644
--- a/Signal/src/ViewControllers/ConversationView/ConversationViewController.m
+++ b/Signal/src/ViewControllers/ConversationView/ConversationViewController.m
@@ -2950,6 +2950,8 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
     if (shouldAnimateUpdates) {
         [self.collectionView performBatchUpdates:batchUpdates completion:batchUpdatesCompletion];
     } else {
+        // We want these animations to be as short as possible, but `performBatchUpdates`
+        // will SIGABORT in some cases if the animation duration is zero.
         [CATransaction begin];
         [CATransaction setAnimationDuration:0.05f];
         [self.collectionView performBatchUpdates:batchUpdates completion:batchUpdatesCompletion];