Change how we detect the default locale

Previously, we would just ask ICU what it thought the default locale
was, since that seemed like a reasonable thing to do. However, in cases
where LANG, LC_MESSAGES and LC_ALL where unset and setlocale(3) returned
"C", ICU would use "en-US-POSIX" as a default locale.

The above case is actually what happens by default when you are running
in docker and en-US-POSIX has very odd collation rules (ASCII characters
which differ only by case are still treated as seperate letters) which
trip folks up.

So in this case, we'll use Invariant. If setlocale(3) returns a non
C/POSIX locale or any of LANG, LC_MESSAGES, or LC_ALL are set to non
empty values, we'll continue to let ICU figure out what to do.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/corefx/System.Globalization.Native/localeStringData.cpp b/src/corefx/System.Globalization.Native/localeStringData.cpp
index 6adb38f9ac..927da67095 100644
--- a/src/corefx/System.Globalization.Native/localeStringData.cpp
+++ b/src/corefx/System.Globalization.Native/localeStringData.cpp
@@ -179,7 +179,7 @@ extern "C" int32_t GlobalizationNative_GetLocaleInfoString(
     switch (localeStringData)
     {
         case LocalizedDisplayName:
-            uloc_getDisplayName(locale, uloc_getDefault(), value, valueLength, &status);
+            uloc_getDisplayName(locale, DetectDefaultLocaleName(), value, valueLength, &status);
             break;
         case EnglishDisplayName:
             uloc_getDisplayName(locale, ULOC_ENGLISH, value, valueLength, &status);
@@ -188,7 +188,7 @@ extern "C" int32_t GlobalizationNative_GetLocaleInfoString(
             uloc_getDisplayName(locale, locale, value, valueLength, &status);
             break;
         case LocalizedLanguageName:
-            uloc_getDisplayLanguage(locale, uloc_getDefault(), value, valueLength, &status);
+            uloc_getDisplayLanguage(locale, DetectDefaultLocaleName(), value, valueLength, &status);
             break;
         case EnglishLanguageName:
             uloc_getDisplayLanguage(locale, ULOC_ENGLISH, value, valueLength, &status);