Fix weird crashes when switching accounts

The use an unowned reference to self because when the cell is deinit'd,
the Combine observers will be cancelled.

Tusker/LocalData.swift

@@ -21,6 +21,7 @@ class LocalData: ObservableObject {
             if ProcessInfo.processInfo.environment.keys.contains("UI_TESTING_LOGIN") {
                 accounts = [
                     UserAccountInfo(
+                        id: UUID().uuidString,
                         instanceURL: URL(string: "http://localhost:8080")!,
                         clientID: "client_id",
                         clientSecret: "client_secret",
@@ -38,15 +39,16 @@ class LocalData: ObservableObject {
         get {
             if let array = defaults.array(forKey: accountsKey) as? [[String: String]] {
                 return array.compactMap { (info) in
-                    guard let instanceURL = info["instanceURL"],
+                    guard let id = info["id"],
+                        let instanceURL = info["instanceURL"],
                         let url = URL(string: instanceURL),
-                        let id = info["clientID"],
+                        let clientId = info["clientID"],
                         let secret = info["clientSecret"],
                         let username = info["username"],
                         let accessToken = info["accessToken"] else {
                             return nil
                     }
-                    return UserAccountInfo(instanceURL: url, clientID: id, clientSecret: secret, username: username, accessToken: accessToken)
+                    return UserAccountInfo(id: id, instanceURL: url, clientID: clientId, clientSecret: secret, username: username, accessToken: accessToken)
                 }
             } else {
                 return []
@@ -56,6 +58,7 @@ class LocalData: ObservableObject {
             objectWillChange.send()
             let array = newValue.map { (info) in
                 return [
+                    "id": info.id,
                     "instanceURL": info.instanceURL.absoluteString,
                     "clientID": info.clientID,
                     "clientSecret": info.clientSecret,
@@ -68,7 +71,7 @@ class LocalData: ObservableObject {
     }
     
     private let mostRecentAccountKey = "mostRecentAccount"
-    var mostRecentAccount: String? {
+    private var mostRecentAccount: String? {
         get {
             return defaults.string(forKey: mostRecentAccountKey)
         }
@@ -82,41 +85,60 @@ class LocalData: ObservableObject {
         return !accounts.isEmpty
     }
     
-    func addAccount(instanceURL url: URL, clientID id: String, clientSecret secret: String, username: String, accessToken: String) -> UserAccountInfo {
+    func addAccount(instanceURL url: URL, clientID: String, clientSecret secret: String, username: String, accessToken: String) -> UserAccountInfo {
         var accounts = self.accounts
         if let index = accounts.firstIndex(where: { $0.instanceURL == url && $0.username == username }) {
             accounts.remove(at: index)
         }
-        let info = UserAccountInfo(instanceURL: url, clientID: id, clientSecret: secret, username: username, accessToken: accessToken)
+        let id = UUID().uuidString
+        let info = UserAccountInfo(id: id, instanceURL: url, clientID: clientID, clientSecret: secret, username: username, accessToken: accessToken)
         accounts.append(info)
         self.accounts = accounts
         return info
     }
     
     func removeAccount(_ info: UserAccountInfo) {
-        
+        accounts.removeAll(where: { $0.id == info.id })
     }
     
     func getMostRecentAccount() -> UserAccountInfo? {
-        if let accessToken = mostRecentAccount {
+        guard onboardingComplete else { return nil }
-            return accounts.first { $0.accessToken == accessToken }
+        let mostRecent: UserAccountInfo?
+        if let id = mostRecentAccount {
+            mostRecent = accounts.first { $0.id == id }
         } else {
-            return nil
+            mostRecent = nil
         }
+        return mostRecent ?? accounts.first!
+    }
+    
+    func setMostRecentAccount(_ account: UserAccountInfo?) {
+        mostRecentAccount = account?.id
     }
 
 }
 
 extension LocalData {
     struct UserAccountInfo: Equatable, Hashable {
+        let id: String
         let instanceURL: URL
         let clientID: String
         let clientSecret: String
         let username: String
         let accessToken: String
+        
+        func hash(into hasher: inout Hasher) {
+            hasher.combine(id)
+        }
+        
+        static func ==(lhs: UserAccountInfo, rhs: UserAccountInfo) -> Bool {
+            return lhs.id == rhs.id
+        }
     }
 }
 
 extension Notification.Name {
-    static let userLoggedOut = Notification.Name("userLoggedOut")
+    static let userLoggedOut = Notification.Name("Tusker.userLoggedOut")
+    static let addAccount = Notification.Name("Tusker.addAccount")
+    static let activateAccount = Notification.Name("Tusker.activateAccount")
 }

Tusker/MastodonCache.swift

@@ -20,7 +20,7 @@ class MastodonCache {
     let statusSubject = PassthroughSubject<Status, Never>()
     let accountSubject = PassthroughSubject<Account, Never>()
 
-    let mastodonController: MastodonController
+    weak var mastodonController: MastodonController?
     
     init(mastodonController: MastodonController) {
         self.mastodonController = mastodonController
@@ -43,6 +43,9 @@ class MastodonCache {
     }
     
     func status(for id: String, completion: @escaping (Status?) -> Void) {
+        guard let mastodonController = mastodonController else {
+            fatalError("The MastodonController for this cache has been deinitialized, so this cache should no longer exist. Are you storing a strong reference to it?")
+        }
         let request = Client.getStatus(id: id)
         mastodonController.run(request) { response in
             guard case let .success(status, _) = response else {
@@ -73,6 +76,9 @@ class MastodonCache {
     }
     
     func account(for id: String, completion: @escaping (Account?) -> Void) {
+        guard let mastodonController = mastodonController else {
+            fatalError("The MastodonController for this cache has been deinitialized, so this cache should no longer exist. Are you storing a strong reference to it?")
+        }
         let request = Client.getAccount(id: id)
         mastodonController.run(request) { response in
             guard case let .success(account, _) = response else {
@@ -102,6 +108,9 @@ class MastodonCache {
     }
     
     func relationship(for id: String, completion: @escaping (Relationship?) -> Void) {
+        guard let mastodonController = mastodonController else {
+            fatalError("The MastodonController for this cache has been deinitialized, so this cache should no longer exist. Are you storing a strong reference to it?")
+        }
         let request = Client.getRelationships(accounts: [id])
         mastodonController.run(request) { response in
             guard case let .success(relationships, _) = response,

Tusker/SceneDelegate.swift

@@ -34,7 +34,6 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
         
         window!.makeKeyAndVisible()
         
-        NotificationCenter.default.addObserver(self, selector: #selector(onUserLoggedOut), name: .userLoggedOut, object: nil)
         NotificationCenter.default.addObserver(self, selector: #selector(themePrefChanged), name: .themePreferenceChanged, object: nil)
         themePrefChanged()
         
@@ -110,11 +109,20 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
     }
     
     func activateAccount(_ account: LocalData.UserAccountInfo) {
-        LocalData.shared.mostRecentAccount = account.accessToken
+        LocalData.shared.setMostRecentAccount(account)
         window!.windowScene!.session.mastodonController = MastodonController.getForAccount(account)
         showAppUI()
     }
     
+    func logoutCurrent() {
+        LocalData.shared.removeAccount(LocalData.shared.getMostRecentAccount()!)
+        if LocalData.shared.onboardingComplete {
+            activateAccount(LocalData.shared.accounts.first!)
+        } else {
+            showOnboardingUI()
+        }
+    }
+
     func showAppUI() {
         let mastodonController = window!.windowScene!.session.mastodonController!
         mastodonController.getOwnAccount()
@@ -130,10 +138,6 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
         window!.rootViewController = onboarding
     }
     
-    @objc func onUserLoggedOut() {
-        showOnboardingUI()
-    }
-    
     @objc func themePrefChanged() {
         window?.overrideUserInterfaceStyle = Preferences.shared.theme
     }

Tusker/Screens/Compose/Drafts/DraftsTableViewController.swift

@@ -8,7 +8,7 @@
 
 import UIKit
 
-protocol DraftsTableViewControllerDelegate {
+protocol DraftsTableViewControllerDelegate: class {
     func draftSelectionCanceled()
     func shouldSelectDraft(_ draft: DraftsManager.Draft, completion: @escaping (Bool) -> Void)
     func draftSelected(_ draft: DraftsManager.Draft)
@@ -17,7 +17,7 @@ protocol DraftsTableViewControllerDelegate {
 
 class DraftsTableViewController: UITableViewController {
     
-    var delegate: DraftsTableViewControllerDelegate?
+    weak var delegate: DraftsTableViewControllerDelegate?
     
     init() {
         super.init(nibName: "DraftsTableViewController", bundle: nil)

Tusker/Screens/Main/MainTabBarViewController.swift

@@ -10,7 +10,7 @@ import UIKit
 
 class MainTabBarViewController: UITabBarController, UITabBarControllerDelegate {
     
-    let mastodonController: MastodonController
+    weak var mastodonController: MastodonController!
 
     override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
         if UIDevice.current.userInterfaceIdiom == .phone {

Tusker/Screens/Notifications/NotificationsPageViewController.swift

@@ -14,7 +14,7 @@ class NotificationsPageViewController: SegmentedPageViewController {
     private let notificationsTitle = NSLocalizedString("Notifications", comment: "notifications tab title")
     private let mentionsTitle = NSLocalizedString("Mentions", comment: "mentions tab title")
     
-    let mastodonController: MastodonController
+    weak var mastodonController: MastodonController!
 
     init(mastodonController: MastodonController) {
         self.mastodonController = mastodonController

Tusker/Screens/Onboarding/InstanceSelectorTableViewController.swift

@@ -10,7 +10,7 @@ import UIKit
 import Combine
 import Pachyderm
 
-protocol InstanceSelectorTableViewControllerDelegate {
+protocol InstanceSelectorTableViewControllerDelegate: class {
     func didSelectInstance(url: URL)
 }
 
@@ -18,7 +18,7 @@ fileprivate let instanceCell = "instanceCell"
 
 class InstanceSelectorTableViewController: UITableViewController {
     
-    var delegate: InstanceSelectorTableViewControllerDelegate?
+    weak var delegate: InstanceSelectorTableViewControllerDelegate?
 
     var dataSource: DataSource!
     var searchController: UISearchController!
@@ -55,7 +55,7 @@ class InstanceSelectorTableViewController: UITableViewController {
         tableView.rowHeight = UITableView.automaticDimension
         tableView.estimatedRowHeight = 120
         
-        dataSource = DataSource(tableView: tableView, cellProvider: { (tableView, indexPath, item) -> UITableViewCell? in
+        dataSource = DataSource(tableView: tableView, cellProvider: { [weak self] (tableView, indexPath, item) -> UITableViewCell? in
             switch item {
             case let .selected(instance):
                 let cell = tableView.dequeueReusableCell(withIdentifier: instanceCell, for: indexPath) as! InstanceTableViewCell

Tusker/Screens/Onboarding/OnboardingViewController.swift

@@ -69,9 +69,9 @@ extension OnboardingViewController: InstanceSelectorTableViewControllerDelegate
                 
                 mastodonController.authorize(authorizationCode: authCode) { (accessToken) in
                     mastodonController.getOwnAccount { (account) in
-                        let accountInfo = LocalData.shared.addAccount(instanceURL: instanceURL, clientID: clientID, clientSecret: clientSecret, username: account.username, accessToken: accessToken)
-                        
                         DispatchQueue.main.async {
+                            let accountInfo = LocalData.shared.addAccount(instanceURL: instanceURL, clientID: clientID, clientSecret: clientSecret, username: account.username, accessToken: accessToken)
+                            
                             self.onboardingDelegate?.didFinishOnboarding(account: accountInfo)
                         }
                     }

Tusker/Screens/Preferences/PreferencesNavigationController.swift

@@ -11,6 +11,8 @@ import SwiftUI
 
 class PreferencesNavigationController: UINavigationController {
     
+    private var isSwitchingAccounts = false
+
     init(mastodonController: MastodonController) {
         let view = PreferencesView()
         let hostingController = UIHostingController(rootView: view)
@@ -27,13 +29,16 @@ class PreferencesNavigationController: UINavigationController {
         
         NotificationCenter.default.addObserver(self, selector: #selector(showAddAccount), name: .addAccount, object: nil)
         NotificationCenter.default.addObserver(self, selector: #selector(activateAccount(_:)), name: .activateAccount, object: nil)
+        NotificationCenter.default.addObserver(self, selector: #selector(userLoggedOut), name: .userLoggedOut, object: nil)
     }
 
     override func viewWillDisappear(_ animated: Bool) {
         super.viewWillDisappear(animated)
         
-        // workaround for onDisappear not being called when a modally presented UIHostingController is dismissed
+        if !isSwitchingAccounts {
-        NotificationCenter.default.post(name: .preferencesChanged, object: nil)
+            // workaround for onDisappear not being called when a modally presented UIHostingController is dismissed
+            NotificationCenter.default.post(name: .preferencesChanged, object: nil)
+        }
     }
 
     @objc func donePressed() {
@@ -48,26 +53,37 @@ class PreferencesNavigationController: UINavigationController {
     }
     
     @objc func cancelAddAccount() {
-        dismiss(animated: true)
+        dismiss(animated: true) // dismisses instance selector
     }
     
     @objc func activateAccount(_ notification: Notification) {
         let account = notification.userInfo!["account"] as! LocalData.UserAccountInfo
         let sceneDelegate = self.view.window!.windowScene!.delegate as! SceneDelegate
-        dismiss(animated: true) {
+        isSwitchingAccounts = true
+        dismiss(animated: true) { // dismiss preferences
             sceneDelegate.activateAccount(account)
         }
     }
     
+    @objc func userLoggedOut() {
+        let sceneDelegate = self.view.window!.windowScene!.delegate as! SceneDelegate
+        isSwitchingAccounts = true
+        dismiss(animated: true) { // dismiss preferences
+            sceneDelegate.logoutCurrent()
+        }
+    }
+
 }
 
-extension Notification.Name {
-    static let addAccount = Notification.Name("Tusker.addAccount")
-    static let activateAccount = Notification.Name("Tusker.activateAccount")
-}
-
 extension PreferencesNavigationController: OnboardingViewControllerDelegate {
     func didFinishOnboarding(account: LocalData.UserAccountInfo) {
-        LocalData.shared.mostRecentAccount = account.accessToken
+        DispatchQueue.main.async {
+            let sceneDelegate = self.view.window!.windowScene!.delegate as! SceneDelegate
+            self.dismiss(animated: true) { // dismiss instance selector
+                self.dismiss(animated: true) { // dismiss preferences
+                    sceneDelegate.activateAccount(account)
+                }
+            }
+        }
     }
 }

Tusker/Screens/Preferences/PreferencesView.swift

@@ -24,7 +24,7 @@ struct PreferencesView: View {
                                 Text(account.username)
                                     .foregroundColor(.primary)
                                 Spacer()
-                                if account.accessToken == self.localData.mostRecentAccount {
+                                if account == self.localData.getMostRecentAccount() {
                                     Image(systemName: "checkmark")
                                         .renderingMode(.template)
                                         .foregroundColor(.secondary)
@@ -37,7 +37,7 @@ struct PreferencesView: View {
                     }) {
                         Text("Add Account...")
                     }
-                    if localData.mostRecentAccount != nil {
+                    if localData.getMostRecentAccount() != nil {
                         Button(action: {
                             self.showingLogoutConfirmation = true
                         }) {
@@ -73,8 +73,6 @@ struct PreferencesView: View {
     }
     
     func logoutPressed() {
-//        LocalData.shared.removeAccount(currentAccount)
-        localData.removeAccount(localData.getMostRecentAccount()!)
         NotificationCenter.default.post(name: .userLoggedOut, object: nil)
     }
 }

Tusker/Screens/Profile/ProfileTableViewController.swift

@@ -12,7 +12,7 @@ import SafariServices
 
 class ProfileTableViewController: EnhancedTableViewController {
     
-    let mastodonController: MastodonController
+    weak var mastodonController: MastodonController!
     
     var accountID: String! {
         didSet {

Tusker/Screens/Timeline/InstanceTimelineViewController.swift

@@ -8,14 +8,14 @@
 
 import UIKit
 
-protocol InstanceTimelineViewControllerDelegate {
+protocol InstanceTimelineViewControllerDelegate: class {
     func didSaveInstance(url: URL)
     func didUnsaveInstance(url: URL)
 }
 
 class InstanceTimelineViewController: TimelineTableViewController {
     
-    var delegate: InstanceTimelineViewControllerDelegate?
+    weak var delegate: InstanceTimelineViewControllerDelegate?
 
     let instanceURL: URL
     

Tusker/Screens/Timeline/TimelineTableViewController.swift

@@ -12,7 +12,7 @@ import Pachyderm
 class TimelineTableViewController: EnhancedTableViewController {
     
     var timeline: Timeline!
-    let mastodonController: MastodonController
+    weak var mastodonController: MastodonController!
     
     var timelineSegments: [[(id: String, state: StatusState)]] = [] {
         didSet {

Tusker/Screens/Timeline/TimelinesPageViewController.swift

@@ -14,7 +14,7 @@ class TimelinesPageViewController: SegmentedPageViewController {
     private let federatedTitle = NSLocalizedString("Federated", comment: "federated timeline tab title")
     private let localTitle = NSLocalizedString("Local", comment: "local timeline tab title")
     
-    let mastodonController: MastodonController
+    weak var mastodonController: MastodonController!
     
     init(mastodonController: MastodonController) {
         self.mastodonController = mastodonController

Tusker/TuskerNavigationDelegate.swift

@@ -10,7 +10,7 @@ import UIKit
 import SafariServices
 import Pachyderm
 
-protocol TuskerNavigationDelegate {
+protocol TuskerNavigationDelegate: class {
     
     var apiController: MastodonController { get }
     

Tusker/Views/Account Cell/AccountTableViewCell.swift

@@ -10,7 +10,7 @@ import UIKit
 
 class AccountTableViewCell: UITableViewCell {
 
-    var delegate: TuskerNavigationDelegate?
+    weak var delegate: TuskerNavigationDelegate?
     var mastodonController: MastodonController! { delegate?.apiController }
     
     @IBOutlet weak var avatarImageView: UIImageView!

Tusker/Views/Attachments/AttachmentView.swift

@@ -11,13 +11,13 @@ import Pachyderm
 import Gifu
 import AVFoundation
 
-protocol AttachmentViewDelegate {
+protocol AttachmentViewDelegate: class {
     func showAttachmentsGallery(startingAt index: Int)
 }
 
 class AttachmentView: UIImageView, GIFAnimatable {
     
-    var delegate: AttachmentViewDelegate?
+    weak var delegate: AttachmentViewDelegate?
 
     var playImageView: UIImageView!
     
@@ -71,8 +71,8 @@ class AttachmentView: UIImageView, GIFAnimatable {
     }
     
     func loadImage() {
-        ImageCache.attachments.get(attachment.url) { (data) in
+        ImageCache.attachments.get(attachment.url) { [weak self] (data) in
-            guard let data = data else { return }
+            guard let self = self, let data = data else { return }
             DispatchQueue.main.async {
                 if self.attachment.url.pathExtension == "gif" {
                     self.animate(withGIFData: data)

Tusker/Views/Attachments/AttachmentsContainerView.swift

@@ -11,7 +11,7 @@ import Pachyderm
 
 class AttachmentsContainerView: UIView {
 
-    var delegate: AttachmentViewDelegate?
+    weak var delegate: AttachmentViewDelegate?
     
     var statusID: String!
     var attachments: [Attachment]!

Tusker/Views/Compose Media/ComposeMediaView.swift

@@ -10,14 +10,14 @@ import UIKit
 import Photos
 import AVFoundation
 
-protocol ComposeMediaViewDelegate {
+protocol ComposeMediaViewDelegate: class {
     func didRemoveMedia(_ mediaView: ComposeMediaView)
     func descriptionTextViewDidChange(_ mediaView: ComposeMediaView)
 }
 
 class ComposeMediaView: UIView {
 
-    var delegate: ComposeMediaViewDelegate?
+    weak var delegate: ComposeMediaViewDelegate?
     
     @IBOutlet weak var imageView: UIImageView!
     @IBOutlet weak var descriptionTextView: UITextView!

Tusker/Views/ContentTextView.swift

@@ -15,8 +15,7 @@ private let emojiRegex = try! NSRegularExpression(pattern: ":(\\w+):", options:
 
 class ContentTextView: LinkTextView {
     
-    // todo: should be weak
+    weak var navigationDelegate: TuskerNavigationDelegate?
-    var navigationDelegate: TuskerNavigationDelegate?
     var mastodonController: MastodonController? { navigationDelegate?.apiController }
     
     var defaultFont: UIFont = .systemFont(ofSize: 17)

Tusker/Views/Hashtag Cell/HashtagTableViewCell.swift

@@ -11,7 +11,7 @@ import Pachyderm
 
 class HashtagTableViewCell: UITableViewCell {
 
-    var delegate: TuskerNavigationDelegate?
+    weak var delegate: TuskerNavigationDelegate?
 
     @IBOutlet weak var hashtagLabel: UILabel!
     

Tusker/Views/Notifications/ActionNotificationGroupTableViewCell.swift

@@ -12,7 +12,7 @@ import SwiftSoup
 
 class ActionNotificationGroupTableViewCell: UITableViewCell {
 
-    var delegate: TuskerNavigationDelegate?
+    weak var delegate: TuskerNavigationDelegate?
     var mastodonController: MastodonController! { delegate?.apiController }
     
     @IBOutlet weak var actionImageView: UIImageView!
@@ -27,6 +27,10 @@ class ActionNotificationGroupTableViewCell: UITableViewCell {
     var authorAvatarURL: URL?
     var updateTimestampWorkItem: DispatchWorkItem?
     
+    deinit {
+        updateTimestampWorkItem?.cancel()
+    }
+    
     override func awakeFromNib() {
         super.awakeFromNib()
         
@@ -110,7 +114,9 @@ class ActionNotificationGroupTableViewCell: UITableViewCell {
             delay = nil
         }
         if let delay = delay {
-            updateTimestampWorkItem = DispatchWorkItem(block: self.updateTimestamp)
+            updateTimestampWorkItem = DispatchWorkItem { [unowned self] in
+                self.updateTimestamp()
+            }
             DispatchQueue.main.asyncAfter(deadline: .now() + delay, execute: updateTimestampWorkItem!)
         } else {
             updateTimestampWorkItem = nil

Tusker/Views/Notifications/FollowNotificationGroupTableViewCell.swift

@@ -11,7 +11,7 @@ import Pachyderm
 
 class FollowNotificationGroupTableViewCell: UITableViewCell {
 
-    var delegate: TuskerNavigationDelegate?
+    weak var delegate: TuskerNavigationDelegate?
     var mastodonController: MastodonController! { delegate?.apiController }
     
     @IBOutlet weak var avatarStackView: UIStackView!
@@ -22,6 +22,10 @@ class FollowNotificationGroupTableViewCell: UITableViewCell {
     
     var updateTimestampWorkItem: DispatchWorkItem?
     
+    deinit {
+        updateTimestampWorkItem?.cancel()
+    }
+    
     override func awakeFromNib() {
         super.awakeFromNib()
         
@@ -98,7 +102,7 @@ class FollowNotificationGroupTableViewCell: UITableViewCell {
             delay = nil
         }
         if let delay = delay {
-            updateTimestampWorkItem = DispatchWorkItem {
+            updateTimestampWorkItem = DispatchWorkItem { [unowned self] in
                 self.updateTimestamp()
             }
             DispatchQueue.main.asyncAfter(deadline: .now() + delay, execute: updateTimestampWorkItem!)

Tusker/Views/Notifications/FollowRequestNotificationTableViewCell.swift

@@ -11,7 +11,7 @@ import Pachyderm
 
 class FollowRequestNotificationTableViewCell: UITableViewCell {
 
-    var delegate: TuskerNavigationDelegate?
+    weak var delegate: TuskerNavigationDelegate?
     var mastodonController: MastodonController! { delegate?.apiController }
     
     @IBOutlet weak var stackView: UIStackView!
@@ -27,6 +27,10 @@ class FollowRequestNotificationTableViewCell: UITableViewCell {
     
     var updateTimestampWorkItem: DispatchWorkItem?
     
+    deinit {
+        updateTimestampWorkItem?.cancel()
+    }
+    
     override func awakeFromNib() {
         super.awakeFromNib()
         
@@ -72,7 +76,9 @@ class FollowRequestNotificationTableViewCell: UITableViewCell {
             delay = nil
         }
         if let delay = delay {
-            updateTimestampWorkItem = DispatchWorkItem(block: self.updateTimestamp)
+            updateTimestampWorkItem = DispatchWorkItem { [unowned self] in
+                self.updateTimestamp()
+            }
             DispatchQueue.main.asyncAfter(deadline: .now() + delay, execute: updateTimestampWorkItem!)
         } else {
             updateTimestampWorkItem = nil

Tusker/Views/Profile Header/ProfileHeaderTableViewCell.swift

@@ -15,7 +15,7 @@ protocol ProfileHeaderTableViewCellDelegate: TuskerNavigationDelegate {
 
 class ProfileHeaderTableViewCell: UITableViewCell {
     
-    var delegate: ProfileHeaderTableViewCellDelegate?
+    weak var delegate: ProfileHeaderTableViewCellDelegate?
     var mastodonController: MastodonController! { delegate?.apiController }
 
     @IBOutlet weak var headerImageView: UIImageView!

Tusker/Views/Status/BaseStatusTableViewCell.swift

@@ -16,7 +16,7 @@ protocol StatusTableViewCellDelegate: TuskerNavigationDelegate {
 
 class BaseStatusTableViewCell: UITableViewCell {
     
-    var delegate: StatusTableViewCellDelegate? {
+    weak var delegate: StatusTableViewCellDelegate? {
         didSet {
             contentTextView.navigationDelegate = delegate
         }
@@ -100,16 +100,16 @@ class BaseStatusTableViewCell: UITableViewCell {
     open func createObserversIfNecessary() {
         if statusUpdater == nil {
             statusUpdater = mastodonController.cache.statusSubject
-                .filter { $0.id == self.statusID }
+                .filter { [unowned self] in $0.id == self.statusID }
                 .receive(on: DispatchQueue.main)
-                .sink(receiveValue: updateStatusState(status:))
+                .sink { [unowned self] in self.updateStatusState(status: $0) }
         }
         
         if accountUpdater == nil {
             accountUpdater = mastodonController.cache.accountSubject
-                .filter { $0.id == self.accountID }
+                .filter { [unowned self] in $0.id == self.accountID }
                 .receive(on: DispatchQueue.main)
-                .sink(receiveValue: updateUI(account:))
+                .sink { [unowned self] in self.updateUI(account: $0) }
         }
     }
     

Tusker/Views/Status/TimelineStatusTableViewCell.swift

@@ -34,6 +34,7 @@ class TimelineStatusTableViewCell: BaseStatusTableViewCell {
 
     deinit {
         rebloggerAccountUpdater?.cancel()
+        updateTimestampWorkItem?.cancel()
     }
     
     override func awakeFromNib() {
@@ -48,9 +49,9 @@ class TimelineStatusTableViewCell: BaseStatusTableViewCell {
         
         if rebloggerAccountUpdater == nil {
             rebloggerAccountUpdater = mastodonController.cache.accountSubject
-                .filter { $0.id == self.rebloggerID }
+                .filter { [unowned self] in $0.id == self.rebloggerID }
                 .receive(on: DispatchQueue.main)
-                .sink(receiveValue: updateRebloggerLabel(reblogger:))
+                .sink { [unowned self] in self.updateRebloggerLabel(reblogger: $0) }
         }
     }
     
@@ -94,6 +95,7 @@ class TimelineStatusTableViewCell: BaseStatusTableViewCell {
     }
     
     func updateTimestamp() {
+        guard superview != nil else { return }
         guard let status = mastodonController.cache.status(for: statusID) else { fatalError("Missing cached status \(statusID!)") }
         
         timestampLabel.text = status.createdAt.timeAgoString()
@@ -109,7 +111,7 @@ class TimelineStatusTableViewCell: BaseStatusTableViewCell {
             delay = nil
         }
         if let delay = delay {
-            updateTimestampWorkItem = DispatchWorkItem {
+            updateTimestampWorkItem = DispatchWorkItem { [unowned self] in
                 self.updateTimestamp()
             }
             DispatchQueue.main.asyncAfter(deadline: .now() + delay, execute: updateTimestampWorkItem!)