From 8743ce95bdcafd7f894cb573f42a7724469d2c69 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Mon, 10 Jul 2017 23:43:48 +0200
Subject: [PATCH] Make failing tests pass.

To do this needed to change behavior a little in that now binding errors update the target. Previously in the case of a binding error at the first node in the binding chain, we were converting the `BindingNotification` to `UnsetValue` which had the effect of updating the target value. Now we're passing the `BindingNotification` back, we need to make sure this happens. I believe this is the right thing to do as the behavior should be the same no matter where in the binding chain the error occurs. Data validation errors continue to not update the target.
---
 src/Avalonia.Base/AvaloniaObject.cs                       | 8 ++------
 src/Avalonia.Base/PriorityBindingEntry.cs                 | 2 +-
 .../AvaloniaObjectTests_Binding.cs                        | 4 ++--
 .../Avalonia.Base.UnitTests/AvaloniaObjectTests_Direct.cs | 4 ++--
 tests/Avalonia.Markup.Xaml.UnitTests/Data/BindingTests.cs | 4 ++--
 5 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/src/Avalonia.Base/AvaloniaObject.cs b/src/Avalonia.Base/AvaloniaObject.cs
index 7b8da28f53..77cc90dd93 100644
--- a/src/Avalonia.Base/AvaloniaObject.cs
+++ b/src/Avalonia.Base/AvaloniaObject.cs
@@ -665,14 +665,10 @@ namespace Avalonia
             if (notification != null)
             {
                 notification.LogIfError(this, property);
-
-                if (notification.HasValue)
-                {
-                    value = notification.Value;
-                }
+                value = notification.Value;
             }
 
-            if (notification == null || notification.HasValue)
+            if (notification == null || notification.ErrorType == BindingErrorType.Error || notification.HasValue)
             {
                 var metadata = (IDirectPropertyMetadata)property.GetMetadata(GetType());
                 var accessor = (IDirectPropertyAccessor)GetRegistered(property);
diff --git a/src/Avalonia.Base/PriorityBindingEntry.cs b/src/Avalonia.Base/PriorityBindingEntry.cs
index eb7cf5414c..63f582a34c 100644
--- a/src/Avalonia.Base/PriorityBindingEntry.cs
+++ b/src/Avalonia.Base/PriorityBindingEntry.cs
@@ -98,7 +98,7 @@ namespace Avalonia
 
             if (notification != null)
             {
-                if (notification.HasValue)
+                if (notification.HasValue || notification.ErrorType == BindingErrorType.Error)
                 {
                     Value = notification.Value;
                     _owner.Changed(this);
diff --git a/tests/Avalonia.Base.UnitTests/AvaloniaObjectTests_Binding.cs b/tests/Avalonia.Base.UnitTests/AvaloniaObjectTests_Binding.cs
index cbbe809119..66b237de06 100644
--- a/tests/Avalonia.Base.UnitTests/AvaloniaObjectTests_Binding.cs
+++ b/tests/Avalonia.Base.UnitTests/AvaloniaObjectTests_Binding.cs
@@ -314,7 +314,7 @@ namespace Avalonia.Base.UnitTests
                 new InvalidOperationException("Foo"),
                 BindingErrorType.Error));
 
-            Assert.Equal(6.7, target.GetValue(Class1.QuxProperty));
+            Assert.Equal(5.6, target.GetValue(Class1.QuxProperty));
         }
 
         [Fact]
@@ -359,7 +359,7 @@ namespace Avalonia.Base.UnitTests
                     new InvalidOperationException("Foo"),
                     BindingErrorType.Error));
 
-                Assert.Equal(6.7, target.GetValue(Class1.QuxProperty));
+                Assert.Equal(5.6, target.GetValue(Class1.QuxProperty));
                 Assert.True(called);
             }
         }
diff --git a/tests/Avalonia.Base.UnitTests/AvaloniaObjectTests_Direct.cs b/tests/Avalonia.Base.UnitTests/AvaloniaObjectTests_Direct.cs
index 6f6a675b0e..05339c43b0 100644
--- a/tests/Avalonia.Base.UnitTests/AvaloniaObjectTests_Direct.cs
+++ b/tests/Avalonia.Base.UnitTests/AvaloniaObjectTests_Direct.cs
@@ -352,14 +352,14 @@ namespace Avalonia.Base.UnitTests
         }
 
         [Fact]
-        public void BindingError_Does_Not_Cause_Target_Update()
+        public void DataValidationError_Does_Not_Cause_Target_Update()
         {
             var target = new Class1();
             var source = new Subject<object>();
 
             target.Bind(Class1.FooProperty, source);
             source.OnNext("initial");
-            source.OnNext(new BindingNotification(new InvalidOperationException("Foo"), BindingErrorType.Error));
+            source.OnNext(new BindingNotification(new InvalidOperationException("Foo"), BindingErrorType.DataValidationError));
 
             Assert.Equal("initial", target.GetValue(Class1.FooProperty));
         }
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Data/BindingTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Data/BindingTests.cs
index 210ad2ab0b..bd86877404 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Data/BindingTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Data/BindingTests.cs
@@ -302,12 +302,12 @@ namespace Avalonia.Markup.Xaml.UnitTests.Data
 
             // Bind Foo and Bar to the VM.
             target.Bind(OldDataContextTest.FooProperty, fooBinding);
-            //target.Bind(OldDataContextTest.BarProperty, barBinding);
+            target.Bind(OldDataContextTest.BarProperty, barBinding);
             target.DataContext = vm;
 
             // Make sure the control's Foo and Bar properties are read from the VM
             Assert.Equal(1, target.GetValue(OldDataContextTest.FooProperty));
-            //Assert.Equal(2, target.GetValue(OldDataContextTest.BarProperty));
+            Assert.Equal(2, target.GetValue(OldDataContextTest.BarProperty));
 
             // Set DataContext to null.
             target.DataContext = null;