ICU-20103 Using GetLocaleInfoEx to get user default locale instead of using language...

This pull request is to remove COM dependency in ICU, so that ICU does not need to care about if the caller is a UWP or not.

diff --git a/icu4c/source/common/putil.cpp b/icu4c/source/common/putil.cpp
index 229656d640d51071d150a4713622b3edca37d5f5..b9bd396c8a89a54d96e04a1e0def49693c228565 100644 (file)
--- a/icu4c/source/common/putil.cpp
+++ b/icu4c/source/common/putil.cpp
@@ -1703,73 +1703,25 @@ The leftmost codepage (.xxx) wins.
 
     return posixID;
 
-#elif U_PLATFORM_USES_ONLY_WIN32_API
+#elif U_PLATFORM_HAS_WIN32_API
 #define POSIX_LOCALE_CAPACITY 64
     UErrorCode status = U_ZERO_ERROR;
-    char *correctedPOSIXLocale = 0;
+    char *correctedPOSIXLocale = nullptr;
 
     // If we have already figured this out just use the cached value
-    if (gCorrectedPOSIXLocale != NULL) {
+    if (gCorrectedPOSIXLocale != nullptr) {
         return gCorrectedPOSIXLocale;
     }
 
     // No cached value, need to determine the current value
-    static WCHAR windowsLocale[LOCALE_NAME_MAX_LENGTH];
-#if U_PLATFORM_HAS_WINUWP_API == 0 
-    // If not a Universal Windows App, we'll need user default language.
-    // Vista and above should use Locale Names instead of LCIDs
-    int length = GetUserDefaultLocaleName(windowsLocale, UPRV_LENGTHOF(windowsLocale));
-#else
-    // In a UWP app, we want the top language that the application and user agreed upon
-    ComPtr<ABI::Windows::Foundation::Collections::IVectorView<HSTRING>> languageList;
-
-    ComPtr<ABI::Windows::Globalization::IApplicationLanguagesStatics> applicationLanguagesStatics;
-    HRESULT hr = GetActivationFactory(
-        HStringReference(RuntimeClass_Windows_Globalization_ApplicationLanguages).Get(),
-        &applicationLanguagesStatics);
-    if (SUCCEEDED(hr))
-    {
-        hr = applicationLanguagesStatics->get_Languages(&languageList);
-    }
-
-    if (FAILED(hr))
-    {
-        // If there is no application context, then use the top language from the user language profile
-        ComPtr<ABI::Windows::System::UserProfile::IGlobalizationPreferencesStatics> globalizationPreferencesStatics;
-        hr = GetActivationFactory(
-            HStringReference(RuntimeClass_Windows_System_UserProfile_GlobalizationPreferences).Get(),
-            &globalizationPreferencesStatics);
-        if (SUCCEEDED(hr))
-        {
-            hr = globalizationPreferencesStatics->get_Languages(&languageList);
-        }
-    }
+    static WCHAR windowsLocale[LOCALE_NAME_MAX_LENGTH] = {};
+    int length = GetLocaleInfoEx(LOCALE_NAME_USER_DEFAULT, LOCALE_SNAME, windowsLocale, LOCALE_NAME_MAX_LENGTH);
 
-    // We have a list of languages, ICU knows one, so use the top one for our locale
-    HString topLanguage;
-    if (SUCCEEDED(hr))
-    {
-        hr = languageList->GetAt(0, topLanguage.GetAddressOf());
-    }
-
-    if (FAILED(hr))
-    {
-        // Unexpected, use en-US by default
-        if (gCorrectedPOSIXLocale == NULL) {
-            gCorrectedPOSIXLocale = "en_US";
-        }
-
-        return gCorrectedPOSIXLocale;
-    }
-
-    // ResolveLocaleName will get a likely subtags form consistent with Windows behavior.
-    int length = ResolveLocaleName(topLanguage.GetRawBuffer(NULL), windowsLocale, UPRV_LENGTHOF(windowsLocale));
-#endif
-    // Now we should have a Windows locale name that needs converted to the POSIX style,
-    if (length > 0)
+    // Now we should have a Windows locale name that needs converted to the POSIX style.
+    if (length > 0) // If length is 0, then the GetLocaleInfoEx failed.
     {
         // First we need to go from UTF-16 to char (and also convert from _ to - while we're at it.)
-        char modifiedWindowsLocale[LOCALE_NAME_MAX_LENGTH];
+        char modifiedWindowsLocale[LOCALE_NAME_MAX_LENGTH] = {};
 
         int32_t i;
         for (i = 0; i < UPRV_LENGTHOF(modifiedWindowsLocale); i++)
@@ -1817,7 +1769,7 @@ The leftmost codepage (.xxx) wins.
     }
 
     // If unable to find a locale we can agree upon, use en-US by default
-    if (gCorrectedPOSIXLocale == NULL) {
+    if (gCorrectedPOSIXLocale == nullptr) {
         gCorrectedPOSIXLocale = "en_US";
     }
     return gCorrectedPOSIXLocale;