Respond to CR.

Signal/src/ViewControllers/ConversationView/ConversationViewController.m

@@ -3313,10 +3313,13 @@ typedef enum : NSUInteger {
                     ConversationViewItem *_Nullable viewItem = self.viewItemCache[collectionKey.key];
                     if (viewItem) {
                         [self reloadInteractionForViewItem:viewItem];
+                    } else {
+                        hasMalformedRowChange = YES;
                     }
                 } else if (rowChange.indexPath && rowChange.originalIndex < self.viewItems.count) {
                     // Do nothing, this is a pseudo-update generated due to
                     // setCellDrawingDependencyOffsets.
+                    OWSAssert(rowChange.changes == YapDatabaseViewChangedDependency);
                 } else {
                     hasMalformedRowChange = YES;
                 }
@@ -4807,7 +4810,6 @@ typedef enum : NSUInteger {
                                                                  transaction:transaction
                                                            conversationStyle:self.conversationStyle];
             }
-            viewItem.row = (NSInteger)row;
             [viewItems addObject:viewItem];
             OWSAssert(!viewItemCache[interaction.uniqueId]);
             viewItemCache[interaction.uniqueId] = viewItem;

Signal/src/ViewControllers/ConversationView/ConversationViewItem.h

@@ -60,8 +60,6 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType);
 // Used to suppress "group sender" avatars.
 @property (nonatomic) BOOL shouldHideAvatar;
 
-@property (nonatomic) NSInteger row;
-
 @property (nonatomic, readonly) ConversationStyle *conversationStyle;
 
 - (instancetype)init NS_UNAVAILABLE;

Signal/src/ViewControllers/ConversationView/ConversationViewItem.m

@@ -92,7 +92,6 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType)
     _interaction = interaction;
     _isGroupThread = isGroupThread;
     _conversationStyle = conversationStyle;
-    self.row = NSNotFound;
 
     [self ensureViewState:transaction];