fix: restore local tags cleared by a concurrent FetchUser

On a successful UpdateProperties response, merge the server-confirmed tags back
into the local model so a concurrent FetchUser whose response is missing the
just-written tags can't leave the tag cache cleared. Merging (never replacing)
keeps backend-managed tags intact; a "" value removes the tag.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: nan-li

iOS_SDK/OneSignalSDK/OneSignalUser/Source/Executors/OSPropertyOperationExecutor.swift

@@ -246,15 +246,24 @@ class OSPropertyOperationExecutor: OSOperationExecutor {
         }
 
         OneSignalCoreImpl.sharedClient().execute(request) { response in
-            // On success, remove request from cache, and we do need to hydrate
-            // TODO: We need to hydrate after all ? What why ?
+            // On success, remove request from cache
             self.dispatchQueue.async {
                 self.updateRequestQueue.removeAll(where: { $0 == request})
                 OneSignalUserDefaults.initShared().saveCodeableData(forKey: OS_PROPERTIES_EXECUTOR_UPDATE_REQUEST_QUEUE_KEY, withValue: self.updateRequestQueue)
                 if inBackground {
                     OSBackgroundTaskManager.endBackgroundTask(backgroundTaskIdentifier)
                 }
             }
+
+            // Re-assert the tags the server just confirmed by merging them back into the local model,
+            // to remedy a concurrent FetchUser whose response is missing the just-written tags
+            if OneSignalUserManagerImpl.sharedInstance.isCurrentUser(request.identityModel),
+               let properties = response?["properties"] as? [String: Any],
+               let confirmedTags = properties["tags"] as? [String: String],
+               !confirmedTags.isEmpty {
+                OneSignalUserManagerImpl.sharedInstance._user?.propertiesModel.mergeConfirmedTags(confirmedTags)
+            }
+
             if let onesignalId = request.identityModel.onesignalId {
                 if let rywToken = response?["ryw_token"] as? String
                 {

iOS_SDK/OneSignalSDK/OneSignalUser/Source/OSPropertiesModel.swift

@@ -151,6 +151,25 @@ class OSPropertiesModel: OSModel {
         self.set(property: "tags", newValue: tagsToSend)
     }
 
+    /**
+     Merges server-confirmed tags into the local model, without enqueuing a new delta.
+     A value of `""` removes the tag.
+
+     Used to re-assert tags in order to remedy a concurrent FetchUser whose response
+     may be missing the just-written tags.
+     */
+    func mergeConfirmedTags(_ serverTags: [String: String]) {
+        tagsLock.withLock {
+            for (key, value) in serverTags {
+                if value.isEmpty {
+                    self.tags.removeValue(forKey: key)
+                } else {
+                    self.tags[key] = value
+                }
+            }
+        }
+    }
+
     public override func hydrateModel(_ response: [String: Any]) {
         for property in response {
             switch property.key {