From 92a2f25de44afb1db346a9c9d8d806b15ab18321 Mon Sep 17 00:00:00 2001
From: donandren <donandren@gmail.com>
Date: Fri, 20 May 2016 17:32:09 +0300
Subject: [PATCH] make sure member selector is evaluating target value every
 time select is made

---
 .../Templates/MemberSelector.cs                 |  2 ++
 .../Templates/MemberSelectorTests.cs            | 17 +++++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/src/Markup/Avalonia.Markup.Xaml/Templates/MemberSelector.cs b/src/Markup/Avalonia.Markup.Xaml/Templates/MemberSelector.cs
index a901c175c9..be4287605c 100644
--- a/src/Markup/Avalonia.Markup.Xaml/Templates/MemberSelector.cs
+++ b/src/Markup/Avalonia.Markup.Xaml/Templates/MemberSelector.cs
@@ -51,6 +51,8 @@ namespace Avalonia.Markup.Xaml.Templates
 
             object result = _memberValueNode.CurrentValue.Target;
 
+            _expressionNode.Target = null;
+
             if (result == AvaloniaProperty.UnsetValue)
             {
                 return null;
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Templates/MemberSelectorTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Templates/MemberSelectorTests.cs
index 4903ca7b35..7082863c0d 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Templates/MemberSelectorTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Templates/MemberSelectorTests.cs
@@ -157,6 +157,23 @@ namespace Avalonia.Markup.Xaml.UnitTests.Templates
             Assert.Equal(1, selector.Select(data));
         }
 
+        [Fact]
+        public void Should_Support_Change_Of_Target_Value()
+        {
+            var selector = new MemberSelector() { MemberName = "StringValue" };
+
+            var data = new Item()
+            {
+                StringValue = "Value1"
+            };
+
+            Assert.Same("Value1", selector.Select(data));
+
+            data.StringValue = "Value2";
+
+            Assert.Same("Value2", selector.Select(data));
+        }
+
         private class Item
         {
             public Item Child { get; set; }