Fix #2185: loadPersistentStore crash. (#2186)

Client/Application/Delegates/AppDelegate.swift

@@ -107,6 +107,14 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UIViewControllerRestorati
         let profilePrefix = profile.prefs.getBranchPrefix()
         Migration.launchMigrations(keyPrefix: profilePrefix)
 
+        // An attempt to fix #2185.
+        // There's an unknown crash related to database creation, which happens when tabs are being restored.
+        // Our DataControllers uses a mix of static and lazy properties, there is a chance that some
+        // concurrency problems are occuring.
+        // This forces the database to initialize most important lazy properties before doing any other
+        // database related code.
+        // Please note that this is called after bookmark and keychain restoration processes.
+        DataController.shared.lazyInitialization()
         setUpWebServer(profile)
 
         var imageStore: DiskImageStore?

Data/models/DataController.swift

@@ -45,6 +45,11 @@ public class DataController: NSObject {
     public static var shared: DataController = DataController()
     public static var sharedInMemory: DataController = InMemoryDataController()
 
+    /// A possible hacky solution to prevent  #2185 crashes.
+    public func lazyInitialization() {
+        _ = DataController.shared.container
+    }
+
     public func storeExists() -> Bool {
         return FileManager.default.fileExists(atPath: storeURL.path)
     }