fix: Refreshing via Xcode would cause a crash here

AltStore/Managing Apps/AppManager.swift

@@ -1015,11 +1015,18 @@ private extension AppManager
         return group
     }
     
-    func removeAppExtensions(from application: ALTApplication, existingApp: InstalledApp?, extensions: Set<ALTApplication>, _ presentingViewController: UIViewController?, completion: @escaping (Result<Void, Error>) -> Void)
+    func removeAppExtensions(
-    {
+        from application: ALTApplication,
+        existingApp: InstalledApp?,
+        extensions: Set<ALTApplication>,
+        _ presentingViewController: UIViewController?,
+        completion: @escaping (Result<Void, Error>) -> Void
+    ) {
             
-        //App-Extensions: Ensure existing app's extensions and currently installing app's extensions must match
+        // App-Extensions: Ensure existing app's extensions and currently installing app's extensions must match
-        let existingAppEx: Set<InstalledExtension> = existingApp?.appExtensions ?? Set()
+        if let existingApp {
+            _ = RSTAsyncBlockOperation { _ in
+                let existingAppEx: Set<InstalledExtension> = existingApp.appExtensions
                 let currentAppEx: Set<ALTApplication> = application.appExtensions
                 
                 let currentAppExNames  = currentAppEx.map{ appEx in appEx.bundleIdentifier}
@@ -1029,11 +1036,13 @@ private extension AppManager
                     !(existingAppExNames.contains($0.bundleIdentifier))
                 }
                 
+                
                 let isMatching = (currentAppEx.count == existingAppEx.count) && excessExtensions.isEmpty
                 let diagnosticsMsg = "AppManager.removeAppExtensions: App Extensions in existingApp and currentApp are matching: \(isMatching)\n"
                 + "AppManager.removeAppExtensions: existingAppEx: \(existingAppExNames); currentAppEx: \(String(describing: currentAppExNames))\n"
                 print(diagnosticsMsg)
                 
+                
                 // if background mode, then remove only the excess extensions
                 guard let presentingViewController: UIViewController = presentingViewController else {
                     // perform silent extensions cleanup for those that aren't already present in existing app
@@ -1050,9 +1059,12 @@ private extension AppManager
                         return completion(.failure(error))
                     }
                 }
+            }
+        }
      
         guard !application.appExtensions.isEmpty else { return completion(.success(())) }
         
+        DispatchQueue.main.async {
             let firstSentence: String
             
             if UserDefaults.standard.activeAppLimitIncludesExtensions
@@ -1090,6 +1102,7 @@ private extension AppManager
                 }
             })
             
+            if let presentingViewController {
                 alertController.addAction(UIAlertAction(title: NSLocalizedString("Choose App Extensions", comment: ""), style: .default) { (action) in
                     let popoverContentController = AppExtensionViewHostingController(extensions: extensions) { (selection) in
                         do
@@ -1119,18 +1132,14 @@ private extension AppManager
                         popoverPresentationController.sourceRect = CGRect(x: 50, y: 50, width: 4, height: 4)
                         popoverPresentationController.delegate = popoverContentController
                         
-                DispatchQueue.main.async {
                         presentingViewController.present(popoverContentController, animated: true)
                     }
-            }
-            
-
                 })
                 
-        DispatchQueue.main.async {
                 presentingViewController.present(alertController, animated: true)
             }
         }
+    }
     
     private func _install(_ app: AppProtocol, operation appOperation: AppOperation, group: RefreshGroup, context: InstallAppOperationContext? = nil, additionalEntitlements: [ALTEntitlement: Any]? = nil, cacheApp: Bool = true, completionHandler: @escaping (Result<InstalledApp, Error>) -> Void) -> Progress
     {