From b06f10f974379123d5c0c6b54e464e7d3dc943c5 Mon Sep 17 00:00:00 2001
From: yomunsam <yomunsam@outlook.com>
Date: Sat, 7 Mar 2020 19:07:34 +0800
Subject: [PATCH] fix a bug: https://github.com/Cysharp/UniTask/issues/54

---
 Assets/UniRx.Async/UnityAsyncExtensions.cs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Assets/UniRx.Async/UnityAsyncExtensions.cs b/Assets/UniRx.Async/UnityAsyncExtensions.cs
index 77fe595..fdb6cd3 100644
--- a/Assets/UniRx.Async/UnityAsyncExtensions.cs
+++ b/Assets/UniRx.Async/UnityAsyncExtensions.cs
@@ -792,6 +792,11 @@ namespace UniRx.Async
 
             public void UnsafeOnCompleted(Action continuation)
             {
+                if(asyncOperation != null && asyncOperation.isDone)
+                {
+                    continuation?.Invoke();
+                    return;
+                }
                 Error.ThrowWhenContinuationIsAlreadyRegistered(continuationAction);
                 continuationAction = continuation.AsFuncOfT<AsyncOperation>();
                 asyncOperation.completed += continuationAction;