From c30f15522199ccd16bf068318adbac51f9d3ad12 Mon Sep 17 00:00:00 2001
From: Matthew Chen <matthew@signal.org>
Date: Mon, 7 Jan 2019 17:04:07 -0500
Subject: [PATCH] Fix overzealous assert.

---
 .../ConversationView/ConversationViewModel.m                | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Signal/src/ViewControllers/ConversationView/ConversationViewModel.m b/Signal/src/ViewControllers/ConversationView/ConversationViewModel.m
index 3f8eb04fa..3998ae779 100644
--- a/Signal/src/ViewControllers/ConversationView/ConversationViewModel.m
+++ b/Signal/src/ViewControllers/ConversationView/ConversationViewModel.m
@@ -568,7 +568,11 @@ static const int kYapDatabaseRangeMaxLength = 25000;
         return;
     }
     if (diff.addedItemIds.count < 1 && diff.removedItemIds.count < 1 && diff.updatedItemIds.count < 1) {
-        OWSFailDebug(@"Unexpectedly empty diff.");
+        // This probably isn't an error; presumably the modifications
+        // occurred outside the load window.
+        OWSLogDebug(@"Empty diff.");
+        [self.delegate conversationViewModelDidUpdate:ConversationUpdate.minorUpdate];
+        return;
     }
 
     NSMutableSet<NSString *> *diffAddedItemIds = [diff.addedItemIds mutableCopy];