Fix #5597: if sync is running, don't schedule a bg task

Client/Application/AppDelegate.swift

@@ -374,7 +374,7 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UIViewControllerRestorati
         shutdownWebServer = singleShotTimer
 
         if #available(iOS 13.0, *) {
-            scheduleBGSync()
+            scheduleBGSync(application: application)
         } else {
             syncOnDidEnterBackground(application: application)
         }
@@ -549,14 +549,30 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UIViewControllerRestorati
     }
 
     @available(iOS 13.0, *)
-    private func scheduleBGSync() {
-        let request = BGProcessingTaskRequest(identifier: "org.mozilla.ios.sync.part1")
-        request.earliestBeginDate = Date(timeIntervalSinceNow: 1)
-        request.requiresNetworkConnectivity = true
-        do {
-            try BGTaskScheduler.shared.submit(request)
-        } catch {
-            NSLog(error.localizedDescription)
+    private func scheduleBGSync(application: UIApplication) {
+        if profile?.syncManager.isSyncing ?? false {
+            // If syncing, create a bg task because _shutdown() is blocking and might take a few seconds to complete
+            var taskId = UIBackgroundTaskIdentifier(rawValue: 0)
+            taskId = application.beginBackgroundTask(expirationHandler: {
+                application.endBackgroundTask(taskId)
+            })
+
+            DispatchQueue.main.async {
+                self.profile?._shutdown()
+                application.endBackgroundTask(taskId)
+            }
+        } else {
+            // Blocking call, however without sync running it should be instantaneous
+            profile?._shutdown()
+
+            let request = BGProcessingTaskRequest(identifier: "org.mozilla.ios.sync.part1")
+            request.earliestBeginDate = Date(timeIntervalSinceNow: 1)
+            request.requiresNetworkConnectivity = true
+            do {
+                try BGTaskScheduler.shared.submit(request)
+            } catch {
+                NSLog(error.localizedDescription)
+            }
         }
     }
 }

Storage/Rust/RustLogins.swift

@@ -157,16 +157,18 @@ public class RustLogins {
         return error
     }
 
-    public func forceClose() -> NSError? {
-        var error: NSError?
-
+    public func interrupt() {
         do {
             try storage.interrupt()
         } catch let err as NSError {
-            error = err
-
             Sentry.shared.sendWithStacktrace(message: "Error interrupting Logins database", tag: SentryTag.rustLogins, severity: .error, description: err.localizedDescription)
         }
+    }
+
+    public func forceClose() -> NSError? {
+        var error: NSError?
+
+        interrupt()
 
         queue.sync {
             guard isOpen else { return }

Storage/Rust/RustPlaces.swift

@@ -267,6 +267,10 @@ public class RustPlaces {
         return error
     }
 
+    public func interrupt() {
+        api?.interrupt()
+    }
+
     public func forceClose() -> NSError? {
         var error: NSError? = nil