From e85178e0c540869300369752713edfca07e13f3e Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Mon, 28 Dec 2015 16:47:53 +0000
Subject: [PATCH] Unwrap TargetInvocationExceptions.

Calling Delegate.DynamicInvoke wraps any exception - we want to expose
the actual exception to callers.
---
 src/Perspex.Interactivity/RoutedEvent.cs          | 11 ++++++++++-
 tests/Perspex.Controls.UnitTests/TopLevelTests.cs |  3 +--
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/Perspex.Interactivity/RoutedEvent.cs b/src/Perspex.Interactivity/RoutedEvent.cs
index ca865f74d0..3fa8f9aaf5 100644
--- a/src/Perspex.Interactivity/RoutedEvent.cs
+++ b/src/Perspex.Interactivity/RoutedEvent.cs
@@ -5,6 +5,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq.Expressions;
 using System.Reflection;
+using System.Runtime.ExceptionServices;
 
 namespace Perspex.Interactivity
 {
@@ -100,7 +101,15 @@ namespace Perspex.Interactivity
                     ((e.Route == RoutingStrategies.Direct) || (e.Route & sub.Routes) != 0) &&
                     (!e.Handled || sub.AlsoIfHandled))
                 {
-                    sub.Handler.DynamicInvoke(sender, e);
+                    try
+                    {
+                        sub.Handler.DynamicInvoke(sender, e);
+                    }
+                    catch (TargetInvocationException ex)
+                    {
+                        // Unwrap the inner exception.
+                        ExceptionDispatchInfo.Capture(ex.InnerException).Throw();
+                    }
                 }
             }
         }
diff --git a/tests/Perspex.Controls.UnitTests/TopLevelTests.cs b/tests/Perspex.Controls.UnitTests/TopLevelTests.cs
index 9e4e54608c..ea5ecca1f6 100644
--- a/tests/Perspex.Controls.UnitTests/TopLevelTests.cs
+++ b/tests/Perspex.Controls.UnitTests/TopLevelTests.cs
@@ -311,9 +311,8 @@ namespace Perspex.Controls.UnitTests
 
                 target.Template = CreateTemplate();
                 target.Content = child;
-                target.ApplyTemplate();
 
-                Assert.Throws<InvalidOperationException>(() => target.Presenter.ApplyTemplate());
+                Assert.Throws<InvalidOperationException>(() => target.ApplyTemplate());
             }
         }