Make sure we don't reuse an old NSEUserSession after logging out and back in. (#3273)

NSE/Sources/NotificationServiceExtension.swift

@@ -72,7 +72,9 @@ class NotificationServiceExtension: UNNotificationServiceExtension {
         MXLog.info("\(tag) Payload came: \(request.content.userInfo)")
         
         Self.serialQueue.sync {
-            if Self.userSession == nil {
+            // If the session directories have changed, the user has logged out and back in (even if they entered the same user ID).
+            // We can't do this comparison with the access token of the existing session here due to token refresh when using OIDC.
+            if Self.userSession == nil || Self.userSession?.sessionDirectories != credentials.restorationToken.sessionDirectories {
                 // This function might be run concurrently and from different processes
                 // It's imperative that we create **at most** one UserSession/Client per process
                 Task.synchronous { [appHooks] in

NSE/Sources/Other/NSEUserSession.swift

@@ -9,6 +9,8 @@ import Foundation
 import MatrixRustSDK
 
 final class NSEUserSession {
+    let sessionDirectories: SessionDirectories
+    
     private let baseClient: Client
     private let notificationClient: NotificationClient
     private let userID: String
@@ -18,6 +20,8 @@ final class NSEUserSession {
     private let delegateHandle: TaskHandle?
 
     init(credentials: KeychainCredentials, clientSessionDelegate: ClientSessionDelegate, appHooks: AppHooks) async throws {
+        sessionDirectories = credentials.restorationToken.sessionDirectories
+        
         userID = credentials.userID
         if credentials.restorationToken.passphrase != nil {
             MXLog.info("Restoring client with encrypted store.")