From 8e73133ffeeac213ffb47b520d89bd5d15f33e6c Mon Sep 17 00:00:00 2001
From: Michael Kirk <michael@signal.org>
Date: Wed, 21 Aug 2019 10:57:53 -0600
Subject: [PATCH] reload ThreadDetails ViewItem whenever its present

---
 .../ConversationMessageMapping.swift          | 16 +++++++++------
 .../ConversationView/ConversationViewModel.m  | 20 +++++++++++++++++--
 2 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/Signal/src/ViewControllers/ConversationView/ConversationMessageMapping.swift b/Signal/src/ViewControllers/ConversationView/ConversationMessageMapping.swift
index 782624a86c..59378650c5 100644
--- a/Signal/src/ViewControllers/ConversationView/ConversationMessageMapping.swift
+++ b/Signal/src/ViewControllers/ConversationView/ConversationMessageMapping.swift
@@ -109,6 +109,11 @@ public class ConversationMessageMapping: NSObject {
         try update(transaction: transaction)
     }
 
+    @objc
+    var shouldShowThreadDetails: Bool {
+        return !canLoadMore && !isNoteToSelf
+    }
+
     // This is the core method of the class. It updates the state to
     // reflect the latest database state & the current desired length.
     @objc
@@ -152,20 +157,19 @@ public class ConversationMessageMapping: NSObject {
                 beforePivotCount += 1
             }
         }
+        self.canLoadMore = canLoadMore
 
-        if canLoadMore || isNoteToSelf {
-            // The items need to be reversed, since we load them in reverse order.
-            self.loadedInteractions = Array(newInteractions.reversed())
-        } else {
+        if self.shouldShowThreadDetails {
             // We only show the thread details if we're at the start of the conversation
             let details = ThreadDetailsInteraction(thread: self.thread,
                                                    timestamp: NSDate.ows_millisecondTimeStamp())
 
             self.loadedInteractions = [details] + Array(newInteractions.reversed())
+        } else {
+            // The items need to be reversed, since we load them in reverse order.
+            self.loadedInteractions = Array(newInteractions.reversed())
         }
 
-        self.canLoadMore = canLoadMore
-
         // Establish the pivot, if necessary and possible.
         //
         // Deserializing interactions is expensive. We only need to deserialize
diff --git a/Signal/src/ViewControllers/ConversationView/ConversationViewModel.m b/Signal/src/ViewControllers/ConversationView/ConversationViewModel.m
index 656dbdb84e..3348f3521f 100644
--- a/Signal/src/ViewControllers/ConversationView/ConversationViewModel.m
+++ b/Signal/src/ViewControllers/ConversationView/ConversationViewModel.m
@@ -591,6 +591,14 @@ static const int kYapDatabaseRangeMaxLength = 25000;
                                                                                         error:&updateError];
                                                      }];
 
+    // If we have a thread details item, insert it into the updated items. We assume
+    // it always needs to update, because it's rarely actually loaded and can be changed
+    // by a large number of thread updates.
+    if (self.messageMapping.shouldShowThreadDetails) {
+        updatedInteractionIds = [updatedInteractionIds setByAddingObject:OWSThreadDetailsInteraction.ThreadDetailsId];
+    }
+
+
     if (dbError || updateError || !updatedInteractionIds) {
         OWSFailDebug(@"failure: %@, %@", dbError, updateError);
         [self resetMappingWithSneakyTransaction];
@@ -629,13 +637,21 @@ static const int kYapDatabaseRangeMaxLength = 25000;
     YapDatabaseAutoViewConnection *messageDatabaseView =
         [self.uiDatabaseConnection ext:TSMessageDatabaseViewExtensionName];
     OWSAssertDebug([messageDatabaseView isKindOfClass:[YapDatabaseAutoViewConnection class]]);
-    if (![messageDatabaseView hasChangesForGroup:self.thread.uniqueId inNotifications:notifications]) {
+    if (![messageDatabaseView hasChangesForGroup:self.thread.uniqueId inNotifications:notifications]
+        && !self.messageMapping.shouldShowThreadDetails) {
         [self.delegate conversationViewModelDidUpdateWithSneakyTransaction:ConversationUpdate.minorUpdate];
         return;
     }
 
     NSSet<NSString *> *updatedInteractionIds = [self.messageMapping updatedItemIdsFor:notifications];
 
+    // If we have a thread details item, insert it into the updated items. We assume
+    // it always needs to update, because it's rarely actually loaded and can be changed
+    // by a large number of thread updates.
+    if (self.messageMapping.shouldShowThreadDetails) {
+        updatedInteractionIds = [updatedInteractionIds setByAddingObject:OWSThreadDetailsInteraction.ThreadDetailsId];
+    }
+
     [self anyDBDidUpdateWithUpdatedInteractionIds:updatedInteractionIds];
 }
 
@@ -1465,7 +1481,7 @@ static const int kYapDatabaseRangeMaxLength = 25000;
     if ([viewItem.interaction isKindOfClass:OWSThreadDetailsInteraction.class]) {
         // Thread details is not a persisted interaction.
         // It carries no mutable state, so there's no reason to reload it here.
-        interaction = interaction;
+        interaction = viewItem.interaction;
     } else {
         interaction = [TSInteraction anyFetchWithUniqueId:viewItem.interaction.uniqueId transaction:transaction];
     }