If waiting for push device details and got them persisted, re-emit them.

Source/ARTPush.m

@@ -106,7 +106,17 @@ - (ARTPushActivationStateMachine *)activationMachine {
     activationMachine_once_token = &once;
     static id activationMachineInstance;
     dispatch_once(&once, ^{
-        activationMachineInstance = [[ARTPushActivationStateMachine alloc] init:self->_rest];
+        // -[UIApplication delegate] is an UI API call, so needs to be called from main thread.
+        __block id delegate = nil;
+        if ([NSThread isMainThread]) {
+            delegate = UIApplication.sharedApplication.delegate;
+        } else {
+            dispatch_sync(dispatch_get_main_queue(), ^{
+                delegate = UIApplication.sharedApplication.delegate;
+            });
+        }
+
+        activationMachineInstance = [[ARTPushActivationStateMachine alloc] init:self->_rest delegate:delegate];
     });
     return activationMachineInstance;
 }
@@ -169,29 +179,11 @@ + (void)didFailToRegisterForRemoteNotificationsWithError:(NSError *)error rest:(
 }
 
 - (void)activate {
-    if (!self.activationMachine.delegate) {
-        dispatch_async(dispatch_get_main_queue(), ^{
-            // -[UIApplication delegate] is an UI API call
-            self.activationMachine.delegate = UIApplication.sharedApplication.delegate;
-            [self.activationMachine sendEvent:[ARTPushActivationEventCalledActivate new]];
-        });
-    }
-    else {
-        [self.activationMachine sendEvent:[ARTPushActivationEventCalledActivate new]];
-    }
+    [self.activationMachine sendEvent:[ARTPushActivationEventCalledActivate new]];
 }
 
 - (void)deactivate {
-    if (!self.activationMachine.delegate) {
-        dispatch_async(dispatch_get_main_queue(), ^{
-            // -[UIApplication delegate] is an UI API call
-            self.activationMachine.delegate = UIApplication.sharedApplication.delegate;
-            [self.activationMachine sendEvent:[ARTPushActivationEventCalledDeactivate new]];
-        });
-    }
-    else {
-        [self.activationMachine sendEvent:[ARTPushActivationEventCalledDeactivate new]];
-    }
+    [self.activationMachine sendEvent:[ARTPushActivationEventCalledDeactivate new]];
 }
 
 #endif

Source/ARTPushActivationStateMachine+Private.h

@@ -19,6 +19,7 @@ extern NSString *const ARTPushActivationPendingEventsKey;
 
 @property (nonatomic, strong) ARTRestInternal *rest;
 - (instancetype)init:(ARTRestInternal *)rest;
+- (instancetype)init:(ARTRestInternal *)rest delegate:(nullable id)delegate;
 
 @property (weak, nonatomic) id delegate; // weak because delegates outlive their counterpart
 @property (nonatomic, copy, nullable) void (^transitions)(ARTPushActivationEvent *event, ARTPushActivationState *from, ARTPushActivationState *to);

Source/ARTPushActivationStateMachine.m

@@ -35,8 +35,13 @@ @implementation ARTPushActivationStateMachine {
 }
 
 - (instancetype)init:(ARTRestInternal *)rest {
+    return [self init:rest delegate:nil];
+}
+
+- (instancetype)init:(ARTRestInternal *)rest delegate:(id)delegate {
     if (self = [super init]) {
         _rest = rest;
+        _delegate = delegate;
         _queue = _rest.queue;
         _userQueue = _rest.userQueue;
         // Unarchiving
@@ -52,6 +57,14 @@ - (instancetype)init:(ARTRestInternal *)rest {
         if (!_pendingEvents) {
             _pendingEvents = [NSMutableArray array];
         }
+
+        // Due to bug #966, old versions of the library might have led us to an illegal
+        // persisted state: we have a deviceToken, but the persisted push state is WaitingForPushDeviceDetails.
+        // So we need to re-emit the GotPushDeviceDetails event that led us there.
+        if ([_current isKindOfClass:[ARTPushActivationStateWaitingForPushDeviceDetails class]] && rest.device_nosync.deviceToken != nil) {
+            [rest.logger debug:@"ARTPush: re-emitting stored device details for stuck state machine"];
+            [self handleEvent:[ARTPushActivationEventGotPushDeviceDetails new]];
+        }
     }
     return self;
 }

Spec/PushActivationStateMachine.swift

@@ -409,7 +409,25 @@ class PushActivationStateMachine : QuickSpec {
                     }
 
                 }
+
+                // https://github.com/ably/ably-cocoa/issues/966
+                it("when initializing from persistent state with a deviceToken, GotPushDeviceDetails should be re-emitted") {
+                    storage = MockDeviceStorage(startWith: ARTPushActivationStateWaitingForPushDeviceDetails(machine: initialStateMachine))
+                    rest.internal.storage = storage
+                    rest.device.setAndPersistDeviceToken("foo")
+                    defer { rest.device.setAndPersistDeviceToken(nil) }
+
+                    var registered = false
+
+                    let delegate = StateMachineDelegateCustomCallbacks()
+                    stateMachine = ARTPushActivationStateMachine(rest.internal, delegate: delegate)
+                    delegate.onPushCustomRegister = { error, deviceDetails in
+                        registered = true
+                        return nil
+                    }
 
+                    expect(registered).toEventually(beTrue())
+                }
             }
 
             // RSH3c