always put typing indicator last

Signal/src/ViewControllers/ConversationView/ConversationViewModel.m

@@ -1166,8 +1166,7 @@ static const int kYapDatabaseRangeMinLength = 0;
     [self ensureConversationProfileState];
 
     __block BOOL hasError = NO;
-    [self.uiDatabaseConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
-        id<ConversationViewItem> (^tryToAddViewItem)(TSInteraction *) = ^(TSInteraction *interaction) {
+    id<ConversationViewItem> (^tryToAddViewItem)(TSInteraction *, YapDatabaseReadTransaction *) = ^(TSInteraction *interaction, YapDatabaseReadTransaction *transaction) {
         OWSAssertDebug(interaction.uniqueId.length > 0);
 
         id<ConversationViewItem> _Nullable viewItem = self.viewItemCache[interaction.uniqueId];
@@ -1183,6 +1182,7 @@ static const int kYapDatabaseRangeMinLength = 0;
         return viewItem;
     };
 
+    [self.uiDatabaseConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
         NSMutableArray<TSInteraction *> *interactions = [NSMutableArray new];
         NSMutableSet<NSString *> *interactionIds = [NSMutableSet new];
 
@@ -1217,7 +1217,7 @@ static const int kYapDatabaseRangeMinLength = 0;
                                                  loadedInteractions:interactions
                                                    canLoadMoreItems:canLoadMoreItems];
         if (offers && [interactionIds containsObject:offers.beforeInteractionId]) {
-            id<ConversationViewItem> offersItem = tryToAddViewItem(offers);
+            id<ConversationViewItem> offersItem = tryToAddViewItem(offers, transaction);
             if ([offersItem.interaction isKindOfClass:[OWSContactOffersInteraction class]]) {
                 OWSContactOffersInteraction *oldOffers = (OWSContactOffersInteraction *)offersItem.interaction;
                 BOOL didChange = (oldOffers.hasBlockOffer != offers.hasBlockOffer
@@ -1232,25 +1232,27 @@ static const int kYapDatabaseRangeMinLength = 0;
         }
 
         for (TSInteraction *interaction in interactions) {
-            tryToAddViewItem(interaction);
+            tryToAddViewItem(interaction, transaction);
         }
+    }];
+
+    // This will usually be redundant, but this will resolve one of the symptoms
+    // of the "corrupt YDB view" issue caused by multi-process writes.
+    [viewItems sortUsingComparator:^NSComparisonResult(id<ConversationViewItem> left, id<ConversationViewItem> right) {
+        return [left.interaction compareForSorting:right.interaction];
+    }];
 
     if (self.typingIndicatorsSender) {
+        [self.uiDatabaseConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
             id<ConversationViewItem> _Nullable lastViewItem = viewItems.lastObject;
             uint64_t typingIndicatorTimestamp = (lastViewItem ? lastViewItem.interaction.timestamp + 1 : 1);
             TSInteraction *interaction =
             [[OWSTypingIndicatorInteraction alloc] initWithThread:self.thread
                                                         timestamp:typingIndicatorTimestamp
                                                       recipientId:self.typingIndicatorsSender];
-            tryToAddViewItem(interaction);
-        }
-    }];
-
-    // This will usually be redundant, but this will resolve one of the symptoms
-    // of the "corrupt YDB view" issue caused by multi-process writes.
-    [viewItems sortUsingComparator:^NSComparisonResult(id<ConversationViewItem> left, id<ConversationViewItem> right) {
-        return [left.interaction compareForSorting:right.interaction];
+            tryToAddViewItem(interaction, transaction);
         }];
+    }
 
     // Flag to ensure that we only increment once per launch.
     if (hasError) {