From e0a8248fba84bd21920dc45c91c9f18e1fd99128 Mon Sep 17 00:00:00 2001
From: Max Katz <maxkatz6@outlook.com>
Date: Thu, 14 Jan 2021 21:31:17 -0500
Subject: [PATCH] Close tooltip on null Tip value

---
 src/Avalonia.Controls/ToolTipService.cs | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/Avalonia.Controls/ToolTipService.cs b/src/Avalonia.Controls/ToolTipService.cs
index 9e0bf60f42..f6458c2112 100644
--- a/src/Avalonia.Controls/ToolTipService.cs
+++ b/src/Avalonia.Controls/ToolTipService.cs
@@ -38,9 +38,16 @@ namespace Avalonia.Controls
 
             if (ToolTip.GetIsOpen(control) && e.NewValue != e.OldValue && !(e.NewValue is ToolTip))
             {
-                var tip = control.GetValue(ToolTip.ToolTipProperty);
-
-                tip.Content = e.NewValue;
+                if (e.NewValue is null)
+                {
+                    Close(control);
+                }
+                else
+                {
+                    var tip = control.GetValue(ToolTip.ToolTipProperty);
+
+                    tip.Content = e.NewValue;
+                }
             }
         }