From 52571ee50e8eaf160d1a9aeda144cecf1eff9e5d Mon Sep 17 00:00:00 2001
From: Jevan Saks <jevansa@microsoft.com>
Date: Mon, 16 Dec 2019 09:31:13 -0800
Subject: [PATCH] Fix IsInFrameworkPackage logic (#1762)

---
 dev/dll/MUXControlsFactory.cpp |  8 --------
 dev/dll/SharedHelpers.cpp      | 13 +++++++------
 dev/dll/dllmain.cpp            | 14 ++++++++++++++
 idl/Microsoft.UI.Xaml.idl      | 14 --------------
 4 files changed, 21 insertions(+), 28 deletions(-)

diff --git a/dev/dll/MUXControlsFactory.cpp b/dev/dll/MUXControlsFactory.cpp
index 635cccc422..d43aba22f5 100644
--- a/dev/dll/MUXControlsFactory.cpp
+++ b/dev/dll/MUXControlsFactory.cpp
@@ -12,14 +12,6 @@
 
 #include "XamlControlsXamlMetaDataProvider.g.cpp"
 
-namespace winrt::Microsoft::UI::Private::Controls
-{
-    namespace factory_implementation { using FrameworkPackageDetector = MUXControlsFactory; }
-    namespace implementation { using FrameworkPackageDetector = XamlMetadataProvider; }
-}
-#include "FrameworkPackageDetector.g.cpp"
-
-
 bool MUXControlsFactory::s_initialized{ false };
 
 void MUXControlsFactory::EnsureInitialized()
diff --git a/dev/dll/SharedHelpers.cpp b/dev/dll/SharedHelpers.cpp
index 8fff319a64..8e4516e083 100644
--- a/dev/dll/SharedHelpers.cpp
+++ b/dev/dll/SharedHelpers.cpp
@@ -263,13 +263,14 @@ bool SharedHelpers::IsInFrameworkPackage()
     static bool isInFrameworkPackage = []() {
         // Special type that we manually list here which is not part of the Nuget dll distribution package. 
         // This is our breadcrumb that we leave to be able to detect at runtime that we're using the framework package.
-        // It's listed only in AppxManifest.xml as an activatable type but it isn't activatable.;
-        // NOTE: calling the "internal" winrt_get_activation_factory in module.g.cpp so we don't raise an exception when
-        // this fails in prerelease builds.
-        
+        // It's listed only in the Framework packages' AppxManifest.xml as an activatable type but only so
+        // that RoGetActivationFactory will change behavior and call our DllGetActivationFactory. It doesn't
+        // mater what comes back for the activationfactory. If it succeeds it means we're running against
+        // the framework package.
+
+        winrt::hstring typeName{ L"Microsoft.UI.Private.Controls.FrameworkPackageDetector"sv};
         winrt::IActivationFactory activationFactory;
-        *winrt::put_abi(activationFactory) = winrt_get_activation_factory(L"Microsoft.UI.Private.Controls.FrameworkPackageDetector"sv);
-        if (activationFactory)
+        if (SUCCEEDED(WINRT_RoGetActivationFactory(winrt::get_abi(typeName), winrt::guid_of<IActivationFactory>(), winrt::put_abi(activationFactory))))
         {
             return true;
         }
diff --git a/dev/dll/dllmain.cpp b/dev/dll/dllmain.cpp
index dd7de05e04..f6b2649104 100644
--- a/dev/dll/dllmain.cpp
+++ b/dev/dll/dllmain.cpp
@@ -28,6 +28,20 @@ STDAPI_(BOOL) DllMain(_In_ HINSTANCE hInstance, _In_ DWORD reason, _In_opt_ void
 
 HRESULT WINAPI DllGetActivationFactory(_In_ HSTRING activatableClassId, _Out_ ::IActivationFactory** factory)
 {
+    // This "FrameworkPackageDetector" class is a breadcrumb to help us detect if we're running in a framework package.
+    // The way this works is that our WinMD does not contain this type so attempting to activate it will fail. However,
+    // our framework package AppX contains an activatable class registration for it, so code that tries to activate
+    // it will succeed in that context.
+    uint32_t length{};
+    wchar_t const* const buffer = WINRT_WindowsGetStringRawBuffer(activatableClassId, &length);
+    std::wstring_view const name{ buffer, length };
+    if (name == L"Microsoft.UI.Private.Controls.FrameworkPackageDetector"sv)
+    {
+        winrt::hstring resources{L"Microsoft.UI.Xaml.Controls.XamlControlsResources"sv};
+        // It doesn't matter *what* we return so return a type that everyone uses.
+        return WINRT_GetActivationFactory(winrt::get_abi(resources), reinterpret_cast<void**>(factory));
+    }
+
     return WINRT_GetActivationFactory(activatableClassId, reinterpret_cast<void**>(factory));
 }
 
diff --git a/idl/Microsoft.UI.Xaml.idl b/idl/Microsoft.UI.Xaml.idl
index a1d64c5a8c..cd277764ca 100644
--- a/idl/Microsoft.UI.Xaml.idl
+++ b/idl/Microsoft.UI.Xaml.idl
@@ -153,20 +153,6 @@ namespace MU_X_XTI_NAMESPACE
     }
 }
 
-namespace MU_PRIVATE_CONTROLS_NAMESPACE
-{
-    // This class is a breadcrumb to help us detect if we're running in a framework package.
-    // The way this works is that our WinMD does not contain this type so attempting to activate it
-    // will fail. However our framework package AppX contains an activatable class registration for
-    // it, so code that tries to activate it will succeed in that context.
-    [WUXC_VERSION_INTERNAL]
-    [webhosthidden]
-    [default_interface]
-    runtimeclass FrameworkPackageDetector
-    {
-    }
-}
-
 namespace MU_XC_NAMESPACE
 {
     [WUXC_VERSION_MUXONLY]