From 4e1e23282591db20e2d629ca882246dc2188f49d Mon Sep 17 00:00:00 2001
From: Matthew Chen <charlesmchen@gmail.com>
Date: Thu, 22 Feb 2018 10:44:05 -0500
Subject: [PATCH] Flush writes from other processes.

---
 .../ConversationViewController.m                 | 16 +++++++++++++---
 SignalServiceKit/src/Storage/OWSStorage.m        | 10 ++++++++--
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/Signal/src/ViewControllers/ConversationView/ConversationViewController.m b/Signal/src/ViewControllers/ConversationView/ConversationViewController.m
index 0bc959291..238ccc786 100644
--- a/Signal/src/ViewControllers/ConversationView/ConversationViewController.m
+++ b/Signal/src/ViewControllers/ConversationView/ConversationViewController.m
@@ -4170,9 +4170,11 @@ typedef enum : NSUInteger {
         if (hasAddedNewItems) {
             NSIndexPath *_Nullable indexPathToShow = [self firstIndexPathAtPreviousLastUnreadTimestamp];
             if (indexPathToShow) {
-                [self.collectionView scrollToItemAtIndexPath:indexPathToShow
-                                            atScrollPosition:UICollectionViewScrollPositionCenteredVertically
-                                                    animated:YES];
+                dispatch_async(dispatch_get_main_queue(), ^{
+                    [self.collectionView scrollToItemAtIndexPath:indexPathToShow
+                                                atScrollPosition:UICollectionViewScrollPositionCenteredVertically
+                                                        animated:YES];
+                });
             }
         }
         self.previousLastUnreadTimestamp = nil;
@@ -4307,6 +4309,14 @@ typedef enum : NSUInteger {
     [self ensureDynamicInteractions];
     [self updateBackButtonUnreadCount];
     [self updateNavigationBarSubtitleLabel];
+
+    // There appears to be a bug in YapDatabase that sometimes delays modifications
+    // made in another process (e.g. the SAE) from showing up in other processes.
+    // There's a simple workaround: a trivial write to the database flushes changes
+    // made from other processes.
+    [self.editingDatabaseConnection setObject:[NSUUID UUID].UUIDString
+                                       forKey:@"conversation_view_noop_mod"
+                                 inCollection:@"temp"];
 }
 
 #pragma mark - ConversationCollectionViewDelegate
diff --git a/SignalServiceKit/src/Storage/OWSStorage.m b/SignalServiceKit/src/Storage/OWSStorage.m
index b424b2aaa..6687f5e57 100644
--- a/SignalServiceKit/src/Storage/OWSStorage.m
+++ b/SignalServiceKit/src/Storage/OWSStorage.m
@@ -76,7 +76,10 @@ typedef NSData *_Nullable (^CreateDatabaseMetadataBlock)(void);
     OWSAssert(delegate);
     OWSAssert(delegate.areAllRegistrationsComplete || self.canWriteBeforeStorageReady);
 
-    OWSBackgroundTask *backgroundTask = [OWSBackgroundTask backgroundTaskWithLabelStr:__PRETTY_FUNCTION__];
+    OWSBackgroundTask *_Nullable backgroundTask = nil;
+    if (CurrentAppContext().isMainApp) {
+        backgroundTask = [OWSBackgroundTask backgroundTaskWithLabelStr:__PRETTY_FUNCTION__];
+    }
     [super readWriteWithBlock:block];
     backgroundTask = nil;
 }
@@ -100,7 +103,10 @@ typedef NSData *_Nullable (^CreateDatabaseMetadataBlock)(void);
     OWSAssert(delegate);
     OWSAssert(delegate.areAllRegistrationsComplete || self.canWriteBeforeStorageReady);
 
-    __block OWSBackgroundTask *backgroundTask = [OWSBackgroundTask backgroundTaskWithLabelStr:__PRETTY_FUNCTION__];
+    __block OWSBackgroundTask *_Nullable backgroundTask = nil;
+    if (CurrentAppContext().isMainApp) {
+        backgroundTask = [OWSBackgroundTask backgroundTaskWithLabelStr:__PRETTY_FUNCTION__];
+    }
     [super asyncReadWriteWithBlock:block completionQueue:completionQueue completionBlock:^{
         if (completionBlock) {
             completionBlock();