Fix a race condition when refreshing My Profile before initial load is complete

Tusker/Screens/Profile/ProfileStatusesViewController.swift

@@ -40,6 +40,11 @@ class ProfileStatusesViewController: DiffableTimelineLikeTableViewController<Pro
         super.viewDidLoad()
         
         tableView.register(UINib(nibName: "TimelineStatusTableViewCell", bundle: .main), forCellReuseIdentifier: "statusCell")
+        
+        // setup the initial snapshot with the sections in the right order, so we don't have to worry about order later
+        var snapshot = Snapshot()
+        snapshot.appendSections([.pinned, .statuses])
+        dataSource.apply(snapshot, animatingDifferences: false)
     }
     
     func updateUI(account: AccountMO) {
@@ -72,6 +77,10 @@ class ProfileStatusesViewController: DiffableTimelineLikeTableViewController<Pro
         }
         
         getStatuses { (response) in
+            guard self.state == .loadingInitial else {
+                return
+            }
+            
             switch response {
             case let .failure(error):
                 completion(.failure(.client(error)))
@@ -83,7 +92,6 @@ class ProfileStatusesViewController: DiffableTimelineLikeTableViewController<Pro
                 self.mastodonController.persistentContainer.addAll(statuses: statuses) {
                     DispatchQueue.main.async {
                         var snapshot = self.dataSource.snapshot()
-                        snapshot.appendSections([.statuses])
                         snapshot.appendItems(statuses.map { Item(id: $0.id, state: .unknown) }, toSection: .statuses)
                         if self.kind == .statuses {
                             self.loadPinnedStatuses(snapshot: { snapshot }, completion: completion)
@@ -110,10 +118,7 @@ class ProfileStatusesViewController: DiffableTimelineLikeTableViewController<Pro
                 self.mastodonController.persistentContainer.addAll(statuses: statuses) {
                     DispatchQueue.main.async {
                         var snapshot = snapshot()
-                        if snapshot.indexOfSection(.pinned) != nil {
-                            snapshot.deleteSections([.pinned])
-                        }
-                        snapshot.insertSections([.pinned], beforeSection: .statuses)
+                        snapshot.deleteItems(snapshot.itemIdentifiers(inSection: .pinned))
                         snapshot.appendItems(statuses.map { Item(id: $0.id, state: .unknown) }, toSection: .pinned)
                         completion(.success(snapshot))
                     }
@@ -209,7 +214,9 @@ class ProfileStatusesViewController: DiffableTimelineLikeTableViewController<Pro
     override func refresh() {
         super.refresh()
         
-        if kind == .statuses {
+        // only refresh pinned if the super call actually succeded (put the state into .loadingNewer)
+        if state == .loadingNewer,
+           kind == .statuses {
             loadPinnedStatuses(snapshot: dataSource.snapshot) { (result) in
                 switch result {
                 case .failure(_):

Tusker/Screens/Utilities/DiffableTimelineLikeTableViewController.swift

@@ -195,7 +195,12 @@ class DiffableTimelineLikeTableViewController<Section: Hashable & CaseIterable,
     // MARK: - RefreshableViewController
     
     func refresh() {
-        guard state != .loadingNewer else { return }
+        // if we're unloaded, there's nothing "newer" to load
+        // if we're performing some other operation, we don't want to step on its toes
+        guard state == .loaded else {
+            self.refreshControl?.endRefreshing()
+            return
+        }
         
         state = .loadingNewer