From 487f3eb10ec6130c031581a53773f5c4211c2f37 Mon Sep 17 00:00:00 2001
From: lindexi <lindexi_gd@163.com>
Date: Sun, 25 Feb 2018 20:21:41 +0800
Subject: [PATCH] check action is null

If the user give the null to InvokeAsync, what is his intention
---
 src/Avalonia.Base/Threading/Dispatcher.cs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/Avalonia.Base/Threading/Dispatcher.cs b/src/Avalonia.Base/Threading/Dispatcher.cs
index 7d29a4f969..cf7acb3e8a 100644
--- a/src/Avalonia.Base/Threading/Dispatcher.cs
+++ b/src/Avalonia.Base/Threading/Dispatcher.cs
@@ -81,12 +81,14 @@ namespace Avalonia.Threading
         /// <inheritdoc/>
         public Task InvokeAsync(Action action, DispatcherPriority priority = DispatcherPriority.Normal)
         {
+            Contract.Requires<ArgumentNullException>(action != null);
             return _jobRunner?.InvokeAsync(action, priority);
         }
 
         /// <inheritdoc/>
         public void Post(Action action, DispatcherPriority priority = DispatcherPriority.Normal)
         {
+            Contract.Requires<ArgumentNullException>(action != null);
             _jobRunner?.Post(action, priority);
         }