From e514d90b7a073c0d95a82703279df507d27593a9 Mon Sep 17 00:00:00 2001
From: Jude Kwashie <judekwashie70@gmail.com>
Date: Fri, 2 Jan 2026 13:39:57 +0000
Subject: [PATCH 1/2] fix(messaging, iOS): scope iOS 18 duplicate notification
 workaround to iOS 18.0 only

---
 .../FLTFirebaseMessagingPlugin.m              | 24 ++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/packages/firebase_messaging/firebase_messaging/ios/firebase_messaging/Sources/firebase_messaging/FLTFirebaseMessagingPlugin.m b/packages/firebase_messaging/firebase_messaging/ios/firebase_messaging/Sources/firebase_messaging/FLTFirebaseMessagingPlugin.m
index 8a89462afbe6..d05243f3b650 100644
--- a/packages/firebase_messaging/firebase_messaging/ios/firebase_messaging/Sources/firebase_messaging/FLTFirebaseMessagingPlugin.m
+++ b/packages/firebase_messaging/firebase_messaging/ios/firebase_messaging/Sources/firebase_messaging/FLTFirebaseMessagingPlugin.m
@@ -355,8 +355,18 @@ - (void)userNotificationCenter:(UNUserNotificationCenter *)center
   // this fix)
   NSString *notificationIdentifier = notification.request.identifier;
 
-  if (notification.request.content.userInfo[@"gcm.message_id"] &&
-      ![notificationIdentifier isEqualToString:_foregroundUniqueIdentifier]) {
+  BOOL shouldCheckForDuplicate = NO;
+#if !TARGET_OS_OSX
+  if (@available(iOS 18.0, *)) {
+    if (!@available(iOS 18.1, *)) {
+      // Only iOS 18.0 specifically
+      shouldCheckForDuplicate =
+          [notificationIdentifier isEqualToString:_foregroundUniqueIdentifier];
+    }
+  }
+#endif
+
+  if (notification.request.content.userInfo[@"gcm.message_id"] && !shouldCheckForDuplicate) {
     NSDictionary *notificationDict =
         [FLTFirebaseMessagingPlugin NSDictionaryFromUNNotification:notification];
     [_channel invokeMethod:@"Messaging#onMessage" arguments:notificationDict];
@@ -385,7 +395,15 @@ - (void)userNotificationCenter:(UNUserNotificationCenter *)center
     }
     completionHandler(presentationOptions);
   }
-  _foregroundUniqueIdentifier = notificationIdentifier;
+
+  // Store notification identifier for iOS 18.0 duplicate detection
+#if !TARGET_OS_OSX
+  if (@available(iOS 18.0, *)) {
+    if (!@available(iOS 18.1, *)) {
+      _foregroundUniqueIdentifier = notificationIdentifier;
+    }
+  }
+#endif
 }
 
 // Called when a user interacts with a notification.

From 4d230ea9ef520473edd9bb54221b099dae913a32 Mon Sep 17 00:00:00 2001
From: Jude Kwashie <judekwashie70@gmail.com>
Date: Mon, 5 Jan 2026 09:59:05 +0000
Subject: [PATCH 2/2] fix(messaging, ios): use message id for iOS 18 duplicate
 filter

---
 .../firebase_messaging/FLTFirebaseMessagingPlugin.m    | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/packages/firebase_messaging/firebase_messaging/ios/firebase_messaging/Sources/firebase_messaging/FLTFirebaseMessagingPlugin.m b/packages/firebase_messaging/firebase_messaging/ios/firebase_messaging/Sources/firebase_messaging/FLTFirebaseMessagingPlugin.m
index d05243f3b650..3d8c9298a4e9 100644
--- a/packages/firebase_messaging/firebase_messaging/ios/firebase_messaging/Sources/firebase_messaging/FLTFirebaseMessagingPlugin.m
+++ b/packages/firebase_messaging/firebase_messaging/ios/firebase_messaging/Sources/firebase_messaging/FLTFirebaseMessagingPlugin.m
@@ -353,20 +353,20 @@ - (void)userNotificationCenter:(UNUserNotificationCenter *)center
   // See this Apple issue: https://forums.developer.apple.com/forums/thread/761597
   // when it has been resolved, "_foregroundUniqueIdentifier" can be removed (i.e. the commit for
   // this fix)
-  NSString *notificationIdentifier = notification.request.identifier;
+  NSDictionary *userInfo = notification.request.content.userInfo;
+  NSString *messageID = userInfo[@"gcm.message_id"];
 
   BOOL shouldCheckForDuplicate = NO;
 #if !TARGET_OS_OSX
   if (@available(iOS 18.0, *)) {
     if (!@available(iOS 18.1, *)) {
       // Only iOS 18.0 specifically
-      shouldCheckForDuplicate =
-          [notificationIdentifier isEqualToString:_foregroundUniqueIdentifier];
+      shouldCheckForDuplicate = [messageID isEqualToString:_foregroundUniqueIdentifier];
     }
   }
 #endif
 
-  if (notification.request.content.userInfo[@"gcm.message_id"] && !shouldCheckForDuplicate) {
+  if (messageID && !shouldCheckForDuplicate) {
     NSDictionary *notificationDict =
         [FLTFirebaseMessagingPlugin NSDictionaryFromUNNotification:notification];
     [_channel invokeMethod:@"Messaging#onMessage" arguments:notificationDict];
@@ -400,7 +400,7 @@ - (void)userNotificationCenter:(UNUserNotificationCenter *)center
 #if !TARGET_OS_OSX
   if (@available(iOS 18.0, *)) {
     if (!@available(iOS 18.1, *)) {
-      _foregroundUniqueIdentifier = notificationIdentifier;
+      _foregroundUniqueIdentifier = messageID;
     }
   }
 #endif