Add fix for stale replace removal

Author: bjtitus

Modules/Server/Sources/PocketCastsServer/Public/Sync/UpNextSyncTask.swift

@@ -132,7 +132,13 @@ class UpNextSyncTask: ApiBaseTask {
             // save the server last modified so we can send it back next time. For legacy compatibility this is stored as a string
             UserDefaults.standard.set("\(response.serverModified)", forKey: ServerConstants.UserDefaults.upNextServerLastModified)
 
-            clearSyncedData(latestActionTime: latestActionTime)
+            // For login syncs, clear all pending changes since we've applied server state
+            // and any pending changes are stale. See: https://github.com/Automattic/pocket-casts-ios/issues/XXXX
+            if SyncManager.syncReason == .login && FeatureFlag.clearPendingUpNextChangesOnLogin.enabled {
+                clearSyncedData(latestActionTime: Int64.max)
+            } else {
+                clearSyncedData(latestActionTime: latestActionTime)
+            }
         } catch {
             FileLog.shared.addMessage("UpNextSyncTask: Failed to decode server data")
         }

Modules/Utils/Sources/PocketCastsUtils/Feature Flags/FeatureFlag.swift

@@ -286,6 +286,9 @@ public enum FeatureFlag: String, CaseIterable {
     /// Use WCSessionFileTransfer to send logs from watchOS to iPhone instead of sendMessage reply
     case watchLogFileTransfer
 
+    /// Clear all pending Up Next changes on login sync to prevent stale replace actions from being sent
+    case clearPendingUpNextChangesOnLogin
+
     public var enabled: Bool {
         if let overriddenValue = FeatureFlagOverrideStore().overriddenValue(for: self) {
             return overriddenValue
@@ -480,6 +483,8 @@ public enum FeatureFlag: String, CaseIterable {
             true
         case .watchLogFileTransfer:
             true
+        case .clearPendingUpNextChangesOnLogin:
+            false
         }
     }