Fixed iOS 10 crash with action buttons

* Crash would only happen if application:didReceiveRemoteNotification:fetchCompletionHandler: was not present in the app when the app is resumed after a notification with action buttons is received.
   - This was due to multiple calls to the completionHandler.

Author: jkasten2

iOS_SDK/OneSignal/OneSignal.m

@@ -1071,7 +1071,9 @@ + (void)didRegisterForRemoteNotifications:(UIApplication*)app deviceToken:(NSDat
     }];
 }
 
-+ (void) remoteSilentNotification:(UIApplication*)application UserInfo:(NSDictionary*)userInfo completionHandler:(void (^)(UIBackgroundFetchResult))completionHandler {
++ (BOOL) remoteSilentNotification:(UIApplication*)application UserInfo:(NSDictionary*)userInfo completionHandler:(void (^)(UIBackgroundFetchResult))completionHandler {
+    BOOL startedBackgroundJob = false;
+    
     // If 'm' present then the notification has action buttons attached to it.
     NSDictionary* data = nil;
 
@@ -1082,6 +1084,7 @@ + (void) remoteSilentNotification:(UIApplication*)application UserInfo:(NSDictio
     // Genergate local notification for action button and/or attachments.
     if (data) {
         if (NSClassFromString(@"UNUserNotificationCenter")) {
+            startedBackgroundJob = true;
             #if XC8_AVAILABLE
             [OneSignalHelper addnotificationRequest:data userInfo:userInfo completionHandler:completionHandler];
             #endif
@@ -1097,7 +1100,7 @@ + (void) remoteSilentNotification:(UIApplication*)application UserInfo:(NSDictio
         if (application.applicationState == UIApplicationStateActive)
             [OneSignalHelper handleNotificationReceived:OSNotificationDisplayTypeNotification];
         [OneSignal notificationOpened:userInfo isActive:NO];
-        return;
+        return startedBackgroundJob;
     }
     // content-available notification received in the background - Fire handleNotificationReceived block in app
     else {
@@ -1107,6 +1110,8 @@ + (void) remoteSilentNotification:(UIApplication*)application UserInfo:(NSDictio
         else
             [OneSignalHelper handleNotificationReceived:OSNotificationDisplayTypeNotification];
     }
+    
+    return startedBackgroundJob;
 }
 
 // iOS 8-9 - Entry point when OneSignal action button notifiation is displayed or opened.

iOS_SDK/OneSignal/OneSignalHelper.m

@@ -684,14 +684,12 @@ + (id)prepareUNNotificationRequest:(NSDictionary *)data :(NSDictionary *)userInf
 }
 
 + (void)addnotificationRequest:(NSDictionary *)data userInfo:(NSDictionary *)userInfo completionHandler:(void (^)(UIBackgroundFetchResult))completionHandler {
-    if (!NSClassFromString(@"UNUserNotificationCenter"))
-        return;
-    
     dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
         [OneSignalHelper beginBackgroundMediaTask];
         id notificationRequest = [OneSignalHelper prepareUNNotificationRequest:data :userInfo];
         [[NSClassFromString(@"UNUserNotificationCenter") currentNotificationCenter] addNotificationRequest:notificationRequest withCompletionHandler:^(NSError * _Nullable error) {}];
-        completionHandler(UIBackgroundFetchResultNewData);
+        if (completionHandler)
+            completionHandler(UIBackgroundFetchResultNewData);
         [OneSignalHelper endBackgroundMediaTask];
     });
 

iOS_SDK/OneSignal/UIApplicationDelegate+OneSignal.m

@@ -40,7 +40,7 @@ + (void) handleDidFailRegisterForRemoteNotification:(NSError*)error;
 + (void) updateNotificationTypes:(int)notificationTypes;
 + (NSString*) app_id;
 + (void) notificationOpened:(NSDictionary*)messageDict isActive:(BOOL)isActive;
-+ (void) remoteSilentNotification:(UIApplication*)application UserInfo:(NSDictionary*)userInfo completionHandler:(void (^)(UIBackgroundFetchResult))completionHandler;
++ (BOOL) remoteSilentNotification:(UIApplication*)application UserInfo:(NSDictionary*)userInfo completionHandler:(void (^)(UIBackgroundFetchResult))completionHandler;
 + (void) processLocalActionBasedNotification:(UILocalNotification*) notification identifier:(NSString*)identifier;
 + (void) onesignal_Log:(ONE_S_LOG_LEVEL)logLevel message:(NSString*) message;
 @end
@@ -180,29 +180,36 @@ - (void)oneSignalReceivedRemoteNotification:(UIApplication*)application userInfo
         [self oneSignalReceivedRemoteNotification:application userInfo:userInfo];
 }
 
-// User Tap on Notification while app was in background - OR - Notification received (silent or not, foreground or background) on iOS 7+
+// Fires when a notication is opened or recieved while the app is in focus.
+//   - Also fires when the app is in the background and a notificaiton with content-available=1 is received.
+// NOTE: completionHandler must only be called once!
+//          iOS 10 - This crashes the app if it is called twice! Crash will happen when the app is resumed.
+//          iOS 9  - Does not have this issue.
 - (void) oneSignalRemoteSilentNotification:(UIApplication*)application UserInfo:(NSDictionary*)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult)) completionHandler {
     [OneSignal onesignal_Log:ONE_S_LL_VERBOSE message:@"oneSignalRemoteSilentNotification:UserInfo:fetchCompletionHandler:"];
 
+    BOOL callExistingSelector = [self respondsToSelector:@selector(oneSignalRemoteSilentNotification:UserInfo:fetchCompletionHandler:)];
+    BOOL startedBackgroundJob = false;
+    
     if ([OneSignal app_id]) {
-        // Call notificationAction if app is active -> not a silent notification but rather user tap on notification
-        // Unless iOS 10+ then call remoteSilentNotification instead.
         if ([UIApplication sharedApplication].applicationState == UIApplicationStateActive && userInfo[@"aps"][@"alert"])
             [OneSignal notificationOpened:userInfo isActive:YES];
         else
-            [OneSignal remoteSilentNotification:application UserInfo:userInfo completionHandler:completionHandler];
+            startedBackgroundJob = [OneSignal remoteSilentNotification:application UserInfo:userInfo completionHandler:callExistingSelector ? nil : completionHandler];
     }
 
-    if ([self respondsToSelector:@selector(oneSignalRemoteSilentNotification:UserInfo:fetchCompletionHandler:)]) {
+    if (callExistingSelector) {
         [self oneSignalRemoteSilentNotification:application UserInfo:userInfo fetchCompletionHandler:completionHandler];
         return;
     }
 
     // Make sure not a cold start from tap on notification (OS doesn't call didReceiveRemoteNotification)
-    if ([self respondsToSelector:@selector(oneSignalReceivedRemoteNotification:userInfo:)] && ![[OneSignal valueForKey:@"coldStartFromTapOnNotification"] boolValue])
+    if ([self respondsToSelector:@selector(oneSignalReceivedRemoteNotification:userInfo:)]
+        && ![[OneSignal valueForKey:@"coldStartFromTapOnNotification"] boolValue])
         [self oneSignalReceivedRemoteNotification:application userInfo:userInfo];
 
-    completionHandler(UIBackgroundFetchResultNewData);
+    if (!startedBackgroundJob)
+        completionHandler(UIBackgroundFetchResultNewData);
 }
 
 - (void) oneSignalLocalNotificationOpened:(UIApplication*)application handleActionWithIdentifier:(NSString*)identifier forLocalNotification:(UILocalNotification*)notification completionHandler:(void(^)()) completionHandler {

iOS_SDK/OneSignal/UNUserNotificationCenter+OneSignal.m

@@ -257,7 +257,7 @@ + (void)callLegacyAppDeletegateSelector:(UNNotification *)notification
                 completionHandler();
             }];
         // Always trigger selector for open events and for non-content-available receive events.
-        //  content-available seema to be an odd expection to iOS 10's fallback rules for legacy selectors.
+        //  content-available seems to be an odd expection to iOS 10's fallback rules for legacy selectors.
         else if ([sharedApp.delegate respondsToSelector:@selector(application:didReceiveRemoteNotification:fetchCompletionHandler:)] &&
                  (!fromPresentNotification ||
                  ![[notification.request.trigger valueForKey:@"_isContentAvailable"] boolValue])) {