Return empty ManifestLanguages list for unpackaged apps

Check if valid language tag is passed to PrimaryLanguageOverride

Author: stefansjfw

dev/MRTCore/mrt/Microsoft.Windows.ApplicationModel.Resources/src/ApplicationLanguages.cpp

@@ -9,6 +9,8 @@
 
 #include <AppModel.Identity.h>
 
+#include "Helper.h"
+
 namespace winrt::Microsoft::Windows::ApplicationModel::Resources::implementation
 {
     hstring ApplicationLanguages::m_language;
@@ -20,7 +22,14 @@ namespace winrt::Microsoft::Windows::ApplicationModel::Resources::implementation
 
     winrt::Windows::Foundation::Collections::IVectorView<hstring> ApplicationLanguages::ManifestLanguages()
     {
-        return winrt::Windows::Globalization::ApplicationLanguages::ManifestLanguages();
+        if (AppModel::Identity::IsPackagedProcess())
+        {
+            return winrt::Windows::Globalization::ApplicationLanguages::ManifestLanguages();
+        }
+        else
+        {
+            return {};
+        }
     }
 
     hstring ApplicationLanguages::PrimaryLanguageOverride()
@@ -33,16 +42,18 @@ namespace winrt::Microsoft::Windows::ApplicationModel::Resources::implementation
 
     void ApplicationLanguages::PrimaryLanguageOverride(hstring const& language)
     {
+        bool isValidLanguageTag = IsWellFormedLanguageTag(language.c_str());
+
+        THROW_HR_IF_MSG(E_INVALIDARG, isValidLanguageTag, "The parameter is incorrect");
+
+        static wil::srwlock lock;
+
+        auto criticalSection {lock.lock_exclusive()};
+        m_language = language;
+
         if (AppModel::Identity::IsPackagedProcess())
         {
             winrt::Windows::Globalization::ApplicationLanguages::PrimaryLanguageOverride(language);
         }
-        else
-        {
-            static wil::srwlock lock;
-
-            auto criticalSection{ lock.lock_exclusive() };
-            m_language = language;
-        }
     }
 } // namespace winrt::Microsoft::Windows::ApplicationModel::Resources::implementation

dev/MRTCore/mrt/Microsoft.Windows.ApplicationModel.Resources/src/ApplicationLanguages.h

@@ -25,4 +25,4 @@ namespace winrt::Microsoft::Windows::ApplicationModel::Resources::factory_implem
     struct ApplicationLanguages : ApplicationLanguagesT<ApplicationLanguages, implementation::ApplicationLanguages>
     {
     };
-} // winrt::Microsoft::Windows::ApplicationModel::Resources::factory_implementation
+} // namespace winrt::Microsoft::Windows::ApplicationModel::Resources::factory_implementation

dev/MRTCore/mrt/Microsoft.Windows.ApplicationModel.Resources/src/Helper.cpp

@@ -86,3 +86,31 @@ HRESULT GetDefaultPriFile(winrt::hstring& filePath)
     bool isPackaged = (hr != HRESULT_FROM_WIN32(APPMODEL_ERROR_NO_PACKAGE));
     return GetDefaultPriFileForCurentModule(isPackaged, filePath);
 }
+
+bool IsWellFormedLanguageTag(const wchar_t* languageTag)
+{
+    // Implementation taken from Platform.h, without accepting semi-colon, as it must be a single language tag
+    if (languageTag == nullptr || *languageTag == L'\0')
+    {
+        return FALSE;
+    }
+
+    BOOLEAN ok = TRUE;
+    PCWSTR test = languageTag;
+
+    while (ok && (*test != L'\0'))
+    {
+        // we accept letters, numbers, dash and semi-colon (as list separator)
+        if (((*test >= L'0') && (*test <= L'9')) || ((*test >= L'a') && (*test <= L'z')) || ((*test >= L'A') && (*test <= L'Z')) ||
+            (*test == L'-'))
+        {
+            test++;
+        }
+        else
+        {
+            ok = FALSE;
+        }
+    }
+
+    return ok && ((test - languageTag) >= 2);
+}

dev/MRTCore/mrt/Microsoft.Windows.ApplicationModel.Resources/src/Helper.h

@@ -4,3 +4,4 @@
 #pragma once
 bool IsResourceNotFound(HRESULT hr);
 HRESULT GetDefaultPriFile(winrt::hstring& path);
+bool IsWellFormedLanguageTag(const wchar_t* languageTag);