From 31e6bb4f72ce61ab69e4c78a04224674033807a9 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Sun, 24 Jul 2022 23:02:39 +0200
Subject: [PATCH] Fix evaluation in presence of multiple animation frames.

---
 src/Avalonia.Base/PropertyStore/ValueStore.cs |  3 ++
 .../AvaloniaObjectTests_Binding.cs            | 29 +++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/src/Avalonia.Base/PropertyStore/ValueStore.cs b/src/Avalonia.Base/PropertyStore/ValueStore.cs
index 01fe597fb3..41f7b1711b 100644
--- a/src/Avalonia.Base/PropertyStore/ValueStore.cs
+++ b/src/Avalonia.Base/PropertyStore/ValueStore.cs
@@ -769,6 +769,9 @@ namespace Avalonia.PropertyStore
             {
                 var frame = _frames[i];
 
+                if (frame.Priority <= BindingPriority.LocalValue)
+                    continue;
+
                 if (frame.IsActive &&
                     frame.TryGetEntry(property, out var entry) && 
                     entry.TryGetValue(out var v))
diff --git a/tests/Avalonia.Base.UnitTests/AvaloniaObjectTests_Binding.cs b/tests/Avalonia.Base.UnitTests/AvaloniaObjectTests_Binding.cs
index 35b8c4c78f..cfb6338384 100644
--- a/tests/Avalonia.Base.UnitTests/AvaloniaObjectTests_Binding.cs
+++ b/tests/Avalonia.Base.UnitTests/AvaloniaObjectTests_Binding.cs
@@ -987,6 +987,35 @@ namespace Avalonia.Base.UnitTests
             subscription.Dispose();
         }
 
+        [Fact]
+        public void Produces_Correct_Values_And_Base_Values_With_Multiple_Animation_Bindings()
+        {
+            var target = new Class1();
+            var source1 = new BehaviorSubject<BindingValue<double>>(12.2);
+            var source2 = new BehaviorSubject<BindingValue<double>>(13.3);
+
+            target.SetValue(Class1.QuxProperty, 11.1);
+            target.Bind(Class1.QuxProperty, source1, BindingPriority.Animation);
+
+            Assert.Equal(12.2, target.GetValue(Class1.QuxProperty));
+            Assert.Equal(11.1, target.GetBaseValue(Class1.QuxProperty));
+
+            target.Bind(Class1.QuxProperty, source2, BindingPriority.Animation);
+
+            Assert.Equal(13.3, target.GetValue(Class1.QuxProperty));
+            Assert.Equal(11.1, target.GetBaseValue(Class1.QuxProperty));
+
+            source2.OnCompleted();
+
+            Assert.Equal(12.2, target.GetValue(Class1.QuxProperty));
+            Assert.Equal(11.1, target.GetBaseValue(Class1.QuxProperty));
+
+            source1.OnCompleted();
+
+            Assert.Equal(11.1, target.GetValue(Class1.QuxProperty));
+            Assert.Equal(11.1, target.GetBaseValue(Class1.QuxProperty));
+        }
+
         /// <summary>
         /// Returns an observable that returns a single value but does not complete.
         /// </summary>