From 556e13cc729c5c38ea0bd3447fa17e67a053e856 Mon Sep 17 00:00:00 2001
From: Niels Andriesse <andriesseniels@gmail.com>
Date: Fri, 30 Jul 2021 10:44:48 +1000
Subject: [PATCH] Fix crash

---
 SignalUtilitiesKit/Messaging/OWSMessageUtils.m | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/SignalUtilitiesKit/Messaging/OWSMessageUtils.m b/SignalUtilitiesKit/Messaging/OWSMessageUtils.m
index 09ab38cb6..9f7d6ea41 100644
--- a/SignalUtilitiesKit/Messaging/OWSMessageUtils.m
+++ b/SignalUtilitiesKit/Messaging/OWSMessageUtils.m
@@ -72,11 +72,13 @@ NS_ASSUME_NONNULL_BEGIN
     [LKStorage readWithBlock:^(YapDatabaseReadTransaction *transaction) {
         YapDatabaseViewTransaction *unreadMessages = [transaction ext:TSUnreadDatabaseViewExtensionName];
         NSArray<NSString *> *allGroups = [unreadMessages allGroups];
+        // FIXME: Confusingly, `allGroups` includes contact threads as well
         for (NSString *groupID in allGroups) {
-            TSGroupThread *thread = [TSGroupThread fetchObjectWithUniqueID:groupID transaction:transaction];
-            if (thread.isMuted) continue;
+            TSThread *thread = [TSThread fetchObjectWithUniqueID:groupID transaction:transaction];
+            if (thread.isMuted) { continue; }
+            BOOL isGroupThread = thread.isGroupThread;
             [unreadMessages enumerateKeysAndObjectsInGroup:groupID
-                                                usingBlock:^(NSString *collection, NSString *key, id object, NSUInteger index, BOOL *stop) {
+                usingBlock:^(NSString *collection, NSString *key, id object, NSUInteger index, BOOL *stop) {
                 if (![object conformsToProtocol:@protocol(OWSReadTracking)]) {
                     return;
                 }
@@ -85,9 +87,11 @@ NS_ASSUME_NONNULL_BEGIN
                     NSLog(@"Found an already read message in the * unread * messages list.");
                     return;
                 }
-                TSIncomingMessage * incomingMessage = (TSIncomingMessage *)object;
-                if (incomingMessage != nil && thread.isOnlyNotifyingForMentions && !incomingMessage.isUserMentioned) {
-                    return;
+                if ([object isKindOfClass:TSIncomingMessage.class] && isGroupThread) {
+                    TSIncomingMessage *incomingMessage = (TSIncomingMessage *)object;
+                    if (((TSGroupThread *)thread).isOnlyNotifyingForMentions && !incomingMessage.isUserMentioned) {
+                        return;
+                    }
                 }
                 count += 1;
             }];