Fix a bug where Terminal may crash or hang at shutdown (#1651)

* Fix a bug where Terminal may crash at shutdown

src/cascadia/TerminalApp/App.cpp

@@ -46,10 +46,8 @@ namespace winrt::TerminalApp::implementation
         // cause you to chase down the rabbit hole of "why is App not
         // registered?" when it definitely is.
 
-        // See GH#1339. This is a workaround for MSFT:22116519
-        // We need this to prevent an occasional crash on teardown
-        AddRef();
-        m_inner.as<::IUnknown>()->Release();
+        // Initialize will become protected or be deleted when GH#1339 (workaround for MSFT:22116519) are fixed.
+        Initialize();
     }
 
     // Method Description:

src/cascadia/TerminalApp/App.idl

@@ -9,6 +9,8 @@ namespace TerminalApp
     {
         App();
 
+        void Initialize();
+
         // For your own sanity, it's better to do setup outside the ctor.
         // If you do any setup in the ctor that ends up throwing an exception,
         // then it might look like TermApp just failed to activate, which will

src/cascadia/TerminalApp/pch.h

@@ -35,6 +35,7 @@
 #include <winrt/Windows.ui.xaml.media.h>
 #include <winrt/Windows.ui.xaml.input.h>
 #include <winrt/Windows.UI.Xaml.Hosting.h>
+#include <winrt/Microsoft.Toolkit.Win32.UI.XamlHost.h>
 
 #include <windows.ui.xaml.media.dxinterop.h>
 

src/cascadia/WindowsTerminal/AppHost.cpp

@@ -41,7 +41,10 @@ AppHost::AppHost() noexcept :
 
 AppHost::~AppHost()
 {
+    // destruction order is important for proper teardown here
+    _window = nullptr;
     _app.Close();
+    _app = nullptr;
 }
 
 // Method Description:
@@ -57,7 +60,6 @@ AppHost::~AppHost()
 // - <none>
 void AppHost::Initialize()
 {
-    _app.Initialize();
     _window->Initialize();
     const auto handle = _window->GetHandle();
     _app.Create(reinterpret_cast<uint64_t>(handle));

src/cascadia/WindowsTerminal/WindowsTerminal.vcxproj

@@ -90,6 +90,16 @@
       <DeploymentContent>true</DeploymentContent>
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </NativeReferenceFile>
+
+    <!--
+      The reason why this is needed for ARM64 is unknown,
+      If not added, the centenial package will fail to include the XamlHost dll.
+    -->
+    <NativeReferenceFile Include="$(OpenConsoleDir)$(Platform)\$(Configuration)\TerminalApp\Microsoft.Toolkit.Win32.UI.XamlHost.dll" Condition="'$(Platform)'=='ARM64'">
+      <DeploymentContent>true</DeploymentContent>
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </NativeReferenceFile>
+
     <!--
       the packaging project wont recurse through our dependencies, you have to
       make sure that if you add a cppwinrt dependency to any of these projects,

src/cascadia/WindowsTerminal/pch.h

@@ -41,7 +41,6 @@ Abstract:
 #include <winrt/Windows.system.h>
 #include <winrt/Windows.Foundation.Collections.h>
 #include <winrt/Windows.UI.Xaml.Hosting.h>
-#include <winrt/Microsoft.Toolkit.Win32.UI.XamlHost.h>
 #include <windows.ui.xaml.hosting.desktopwindowxamlsource.h>
 
 // Additional headers for various xaml features. We need: