From 43ed3e2964bdd9d4636cebcf90412e04a98b49a2 Mon Sep 17 00:00:00 2001
From: Jumar Macato <hikari.netto23@gmail.com>
Date: Wed, 18 Sep 2019 21:53:04 +0800
Subject: [PATCH] Fix transitions since the last PR.

---
 src/Avalonia.Animation/Animatable.cs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/Avalonia.Animation/Animatable.cs b/src/Avalonia.Animation/Animatable.cs
index 2c321b8b28..ca45fb8c4d 100644
--- a/src/Avalonia.Animation/Animatable.cs
+++ b/src/Avalonia.Animation/Animatable.cs
@@ -55,6 +55,11 @@ namespace Avalonia.Animation
             }
             set
             {
+                if (value is null)
+                    return;
+
+                if (_previousTransitions is null)
+                    _previousTransitions = new Dictionary<AvaloniaProperty, IDisposable>();
 
                 SetAndRaise(TransitionsProperty, ref _transitions, value);
             }
@@ -70,7 +75,7 @@ namespace Avalonia.Animation
             if (_transitions is null || _previousTransitions is null || e.Priority == BindingPriority.Animation) return;
 
             // PERF-SENSITIVE: Called on every property change. Don't use LINQ here (too many allocations).
-            foreach (var transition in Transitions)
+            foreach (var transition in _transitions)
             {
                 if (transition.Property == e.Property)
                 {