From 0291605934640004667ba44498efc66da7f985fe Mon Sep 17 00:00:00 2001
From: Ryan Grey <rgrey@scottlogic.co.uk>
Date: Mon, 6 Aug 2018 15:19:05 +0100
Subject: [PATCH] Protect against multiple calls to start/stop handling native
 methods

---
 ios/RNFirebase/notifications/RNFirebaseNotifications.m | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/ios/RNFirebase/notifications/RNFirebaseNotifications.m b/ios/RNFirebase/notifications/RNFirebaseNotifications.m
index 9de4e54f..3a2b6556 100644
--- a/ios/RNFirebase/notifications/RNFirebaseNotifications.m
+++ b/ios/RNFirebase/notifications/RNFirebaseNotifications.m
@@ -99,12 +99,22 @@ RCT_EXPORT_MODULE();
 }
 
 RCT_EXPORT_METHOD(startHandlingNotificationDisplayed) {
+    if(isUserHandlingOnNotificationDisplayed == YES) {
+        return;
+    }
+    
     isUserHandlingOnNotificationDisplayed = YES;
+    
     completionHandlers = [[NSMutableDictionary alloc] init];
 }
 
 RCT_EXPORT_METHOD(stopHandlingNotificationDisplayed) {
+    if(isUserHandlingOnNotificationDisplayed == NO) {
+        return;
+    }
+    
     isUserHandlingOnNotificationDisplayed = NO;
+    
     NSArray *allHandlers = completionHandlers.allValues;
     for (void (^ completionHandler)(UIBackgroundFetchResult) in allHandlers) {
         completionHandler(UIBackgroundFetchResultNoData);