Merge remote-tracking branch 'origin/master' into feature/test-branch

src/Markup/Avalonia.Markup/Data/MultiBinding.cs

@@ -107,6 +107,14 @@ namespace Avalonia.Data
 
         private object ConvertValue(IList<object> values, Type targetType, IMultiValueConverter converter)
         {
+            for (var i = 0; i < values.Count; ++i)
+            {
+                if (values[i] is BindingNotification notification)
+                {
+                    values[i] = notification.Value;
+                }
+            }
+
             var culture = CultureInfo.CurrentCulture;
             var converted = converter.Convert(values, targetType, ConverterParameter, culture);
 

tests/Avalonia.Markup.UnitTests/Data/MultiBindingTests.cs

@@ -113,6 +113,50 @@ namespace Avalonia.Markup.UnitTests.Data
             Assert.Equal("(null)", target.Text);
         }
 
+        [Fact]
+        public void Should_Pass_UnsetValue_To_Converter_For_Broken_Binding()
+        {
+            var source = new { A = 1, B = 2, C = 3 };
+            var target = new TextBlock { DataContext = source };
+
+            var binding = new MultiBinding
+            {
+                Converter = new ConcatConverter(),
+                Bindings = new[]
+                {
+                    new Binding { Path = "A" },
+                    new Binding { Path = "B" },
+                    new Binding { Path = "Missing" },
+                },
+            };
+
+            target.Bind(TextBlock.TextProperty, binding);
+
+            Assert.Equal("1,2,(unset)", target.Text);
+        }
+
+        [Fact]
+        public void Should_Pass_FallbackValue_To_Converter_For_Broken_Binding()
+        {
+            var source = new { A = 1, B = 2, C = 3 };
+            var target = new TextBlock { DataContext = source };
+
+            var binding = new MultiBinding
+            {
+                Converter = new ConcatConverter(),
+                Bindings = new[]
+                {
+                    new Binding { Path = "A" },
+                    new Binding { Path = "B" },
+                    new Binding { Path = "Missing", FallbackValue = "Fallback" },
+                },
+            };
+
+            target.Bind(TextBlock.TextProperty, binding);
+
+            Assert.Equal("1,2,Fallback", target.Text);
+        }
+
         private class ConcatConverter : IMultiValueConverter
         {
             public object Convert(IList<object> values, Type targetType, object parameter, CultureInfo culture)

tests/Avalonia.Markup.Xaml.UnitTests/Data/BindingTests.cs

@@ -1,6 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
 using Avalonia.Controls;
+using Avalonia.Controls.Presenters;
 using Avalonia.Data;
+using Avalonia.Data.Converters;
 using Avalonia.UnitTests;
+using Avalonia.VisualTree;
 using Xunit;
 
 namespace Avalonia.Markup.Xaml.UnitTests.Data
@@ -54,5 +61,51 @@ namespace Avalonia.Markup.Xaml.UnitTests.Data
                 Assert.Equal("bar", textBlock.Text);
             }
         }
+
+        [Fact]
+        public void MultiBinding_TemplatedParent_Works()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<Window xmlns='https://github.com/avaloniaui'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
+        xmlns:local='clr-namespace:Avalonia.Markup.Xaml.UnitTests.Data;assembly=Avalonia.Markup.Xaml.UnitTests'>
+    <TextBox Name='textBox' Text='Foo' Watermark='Bar'>
+        <TextBox.Template>
+            <ControlTemplate>
+                <TextPresenter Name='PART_TextPresenter'>
+                    <TextPresenter.Text>
+                        <MultiBinding Converter='{x:Static local:ConcatConverter.Instance}'>
+                            <Binding RelativeSource='{RelativeSource TemplatedParent}' Path='Text'/>
+                            <Binding RelativeSource='{RelativeSource TemplatedParent}' Path='Watermark'/>
+                        </MultiBinding>
+                    </TextPresenter.Text>
+                </TextPresenter>
+            </ControlTemplate>
+        </TextBox.Template>
+    </TextBox>
+</Window>";
+                var loader = new AvaloniaXamlLoader();
+                var window = (Window)loader.Load(xaml);
+                var textBox = window.FindControl<TextBox>("textBox");
+
+                window.ApplyTemplate();
+                textBox.ApplyTemplate();
+
+                var target = (TextPresenter)textBox.GetVisualChildren().Single();
+                Assert.Equal("Foo,Bar", target.Text);
+            }
+        }
+    }
+
+    public class ConcatConverter : IMultiValueConverter
+    {
+        public static ConcatConverter Instance { get; } = new ConcatConverter();
+
+        public object Convert(IList<object> values, Type targetType, object parameter, CultureInfo culture)
+        {
+            return string.Join(",", values);
+        }
     }
 }