Fix login race condition and JWT FAIL_UNAUTHORIZED blocking callers

1. Split LoginHelper into switchUser() + enqueueLogin() so the
   non-suspend login() can synchronously swap user models (instant,
   no network) while the backend create-user call fires in the
   background. This prevents ANRs on main thread while ensuring
   tags target the correct user after each login() call.
   loginSuspend() also calls switchUser() + enqueueLogin() directly
   (no wrapper method) for clarity.

2. Wake enqueueAndWait waiters on FAIL_UNAUTHORIZED and
   FAIL_PAUSE_OPREPO before re-queuing operations. Re-queued items
   use waiter=null so future retries don't reference stale waiters.
   This prevents loginSuspend from hanging forever when a JWT is
   invalid or the op repo pauses.

Fixes SDK-4338

Made-with: Cursor

Author: AR Abdul Azeez

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/operations/impl/OperationRepo.kt

@@ -288,8 +288,15 @@ internal class OperationRepo(
                     if (externalId != null) {
                         _jwtTokenStore.invalidateJwt(externalId)
                         Logging.warn("Operation execution failed with 401 Unauthorized, JWT invalidated for user: $externalId. Operations re-queued.")
+                        // Unblock any enqueueAndWait callers so loginSuspend doesn't hang.
+                        ops.forEach { it.waiter?.wake(false) }
+                        // Re-queue with waiter = null: the operation is preserved for retry
+                        // (once a new JWT is provided via updateUserJwt), but the original
+                        // waiter is detached since it was already woken above.
                         synchronized(queue) {
-                            ops.reversed().forEach { queue.add(0, it) }
+                            ops.reversed().forEach {
+                                queue.add(0, OperationQueueItem(it.operation, waiter = null, bucket = it.bucket, retries = it.retries))
+                            }
                         }
                         dispatchJwtInvalidatedToApp(externalId)
                     } else {
@@ -331,9 +338,15 @@ internal class OperationRepo(
                     Logging.error("Operation execution failed with eventual retry, pausing the operation repo: $operations")
                     // keep the failed operation and pause the operation repo from executing
                     paused = true
-                    // add back all operations to the front of the queue to be re-executed.
+                    // Unblock any enqueueAndWait callers so loginSuspend doesn't hang.
+                    ops.forEach { it.waiter?.wake(false) }
+                    // Re-queue with waiter = null: the operation is preserved for retry
+                    // on next cold start, but the original waiter is detached since it
+                    // was already woken above.
                     synchronized(queue) {
-                        ops.reversed().forEach { queue.add(0, it) }
+                        ops.reversed().forEach {
+                            queue.add(0, OperationQueueItem(it.operation, waiter = null, bucket = it.bucket, retries = it.retries))
+                        }
                     }
                 }
             }

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/internal/OneSignalImp.kt

@@ -384,14 +384,20 @@ internal class OneSignalImp(
 
         if (isBackgroundThreadingEnabled) {
             waitForInit(operationName = "login")
-            suspendifyOnIO { loginHelper.login(externalId, jwtBearerToken) }
         } else {
             if (!isInitialized) {
                 throw IllegalStateException("Must call 'initWithContext' before 'login'")
             }
+        }
+
+        val context = loginHelper.switchUser(externalId, jwtBearerToken) ?: return
+
+        if (isBackgroundThreadingEnabled) {
+            suspendifyOnIO { loginHelper.enqueueLogin(context) }
+        } else {
             Thread {
                 runBlocking(runtimeIoDispatcher) {
-                    loginHelper.login(externalId, jwtBearerToken)
+                    loginHelper.enqueueLogin(context)
                 }
             }.start()
         }
@@ -695,7 +701,8 @@ internal class OneSignalImp(
             throw IllegalStateException("'initWithContext failed' before 'login'")
         }
 
-        loginHelper.login(externalId, jwtBearerToken)
+        val context = loginHelper.switchUser(externalId, jwtBearerToken) ?: return@withContext
+        loginHelper.enqueueLogin(context)
     }
 
     override suspend fun logoutSuspend() =

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/user/internal/LoginHelper.kt

@@ -15,22 +15,30 @@ class LoginHelper(
     private val jwtTokenStore: JwtTokenStore,
     private val lock: Any,
 ) {
-    suspend fun login(
+    internal data class LoginEnqueueContext(
+        val appId: String,
+        val newIdentityOneSignalId: String,
+        val externalId: String,
+        val existingOneSignalId: String?,
+    )
+
+    /**
+     * Synchronously switches local user models under the login/logout lock.
+     * Returns context needed for [enqueueLogin], or null if the user was
+     * already logged in with [externalId] (no switch needed).
+     */
+    internal fun switchUser(
         externalId: String,
         jwtBearerToken: String? = null,
-    ) {
-        var currentIdentityExternalId: String? = null
-        var currentIdentityOneSignalId: String? = null
-        var newIdentityOneSignalId: String = ""
-
+    ): LoginEnqueueContext? {
         synchronized(lock) {
-            currentIdentityExternalId = identityModelStore.model.externalId
-            currentIdentityOneSignalId = identityModelStore.model.onesignalId
+            val currentExternalId = identityModelStore.model.externalId
+            val currentOneSignalId = identityModelStore.model.onesignalId
 
-            if (currentIdentityExternalId == externalId) {
+            if (currentExternalId == externalId) {
                 jwtTokenStore.putJwt(externalId, jwtBearerToken)
                 operationRepo.forceExecuteOperations()
-                return
+                return null
             }
 
             jwtTokenStore.putJwt(externalId, jwtBearerToken)
@@ -39,23 +47,30 @@ class LoginHelper(
                 identityModel.externalId = externalId
             }
 
-            newIdentityOneSignalId = identityModelStore.model.onesignalId
-        }
+            val newOneSignalId = identityModelStore.model.onesignalId
 
-        val existingOneSignalId =
-            if (configModel.useIdentityVerification == true) {
-                null
-            } else {
-                if (currentIdentityExternalId == null) currentIdentityOneSignalId else null
-            }
+            val existingOneSignalId =
+                if (configModel.useIdentityVerification == true) {
+                    null
+                } else {
+                    if (currentExternalId == null) currentOneSignalId else null
+                }
+
+            return LoginEnqueueContext(configModel.appId, newOneSignalId, externalId, existingOneSignalId)
+        }
+    }
 
+    /**
+     * Enqueues the [LoginUserOperation] and suspends until it completes.
+     */
+    internal suspend fun enqueueLogin(context: LoginEnqueueContext) {
         val result =
             operationRepo.enqueueAndWait(
                 LoginUserOperation(
-                    configModel.appId,
-                    newIdentityOneSignalId,
-                    externalId,
-                    existingOneSignalId,
+                    context.appId,
+                    context.newIdentityOneSignalId,
+                    context.externalId,
+                    context.existingOneSignalId,
                 ),
             )
 

OneSignalSDK/onesignal/core/src/test/java/com/onesignal/core/internal/operations/OperationRepoTests.kt

@@ -954,8 +954,9 @@ class OperationRepoTests : FunSpec({
         operationRepo.start()
         val response = operationRepo.enqueueAndWait(operation)
 
-        // Then
-        response shouldBe true
+        // Then – waiter is woken with false immediately on FAIL_UNAUTHORIZED
+        // (operation is re-queued with waiter=null for retry when a new JWT is provided)
+        response shouldBe false
         verify { jwtTokenStore.invalidateJwt("test-user") }
         handlerCalledWith shouldBe "test-user"
     }
@@ -1011,8 +1012,11 @@ class OperationRepoTests : FunSpec({
         operationRepo.start()
         val response = operationRepo.enqueueAndWait(operation)
 
-        response shouldBe true
+        // Waiter is woken with false immediately; operation re-queued with waiter=null
+        response shouldBe false
         verify { jwtTokenStore.invalidateJwt("test-user") }
+        // The re-queued op (waiter=null) retries asynchronously; wait for it to complete
+        delay(3000)
         coVerify(exactly = 2) { executor.execute(any()) }
     }