Merge branch 'master' into fixes/1436-border-layout-issues

src/Avalonia.Controls/Button.cs

@@ -245,7 +245,7 @@ namespace Avalonia.Controls
         {
             base.OnPointerReleased(e);
 
-            if (e.MouseButton == MouseButton.Left)
+            if (IsPressed && e.MouseButton == MouseButton.Left)
             {
                 e.Device.Capture(null);
                 IsPressed = false;

src/Avalonia.Controls/DropDown.cs

@@ -164,6 +164,7 @@ namespace Avalonia.Controls
                 else
                 {
                     IsDropDownOpen = !IsDropDownOpen;
+                    e.Handled = true;
                 }
             }
             base.OnPointerPressed(e);

src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/BindingExtension.cs

@@ -43,6 +43,7 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions
                 Mode = Mode,
                 Path = pathInfo.Path,
                 Priority = Priority,
+                Source = Source,
                 RelativeSource = pathInfo.RelativeSource ?? RelativeSource,
                 DefaultAnchor = new WeakReference(GetDefaultAnchor((ITypeDescriptorContext)serviceProvider))
             };