[libcxx] [test] Fix moneypunct grouping tests on Windows

[mstorsjo]

Summary

For grouping strings, "\3" and "\3\3" are equivalent.

[• Quuxplusone]

libcxx/test/std/localization/locale.categories/category.monetary/locale.moneypunct.byname/grouping.pass.cpp

93

https://en.cppreference.com/w/cpp/locale/numpunct/grouping
Geesh, this stuff is ridiculous. I buy how \3 and \3\3 are equivalent; but then my next question is, why does the existing code (on non-Windows) return \3\3? Is that due to something at the OS level that's out of our control, or is there some way that libc++ could fix it to sanely return a simple \3 like cppreference says it should?

[mstorsjo]

libcxx/test/std/localization/locale.categories/category.monetary/locale.moneypunct.byname/grouping.pass.cpp

93

Like most of these things, I guess it’s pretty much passthrough from the OS’s locale data. I guess we could fix it up within the library, but I’m not sure if it’s worth it, if they’re both functionally equivalent anyway.

[Mordante]

LGTM!

libcxx/test/std/localization/locale.categories/category.monetary/locale.moneypunct.byname/grouping.pass.cpp

93

Looking at my Linux system
en_US mon_grouping 3;3
fr_FR mon_grouping 3

So these values have this value in the system's locale.
I don't think libc++ should try to fix this, better to fix the system's locale instead.

libcxx/test/std/localization/locale.categories/category.monetary/locale.moneypunct.byname/grouping.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // XFAIL: darwin
 //
 // NetBSD does not support LC_MONETARY at the moment
 // XFAIL: netbsd
 
-// XFAIL: LIBCXX-WINDOWS-FIXME
-
 // REQUIRES: locale.en_US.UTF-8
 // REQUIRES: locale.fr_FR.UTF-8
 // REQUIRES: locale.ru_RU.UTF-8
 // REQUIRES: locale.zh_CN.UTF-8
 
 // <locale>
 
 // class moneypunct_byname<charT, International>
#ifndef TEST_HAS_NO_WIDE_CHARACTERS
         assert(f.grouping() == s || f.grouping() == "");
     }
     {
         Fwt f("C", 1);
         assert(f.grouping() == s || f.grouping() == "");
     }
 #endif
 
+#ifdef _WIN32
+    std::string us_grouping = "\3";
+#else
+    std::string us_grouping = "\3\3";
+#endif
     {
         Fnf f(LOCALE_en_US_UTF_8, 1);
-        assert(f.grouping() == "\3\3");
+        assert(f.grouping() == us_grouping);
     }
     {
         Fnt f(LOCALE_en_US_UTF_8, 1);
-        assert(f.grouping() == "\3\3");
+        assert(f.grouping() == us_grouping);
     }
 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
     {
         Fwf f(LOCALE_en_US_UTF_8, 1);
-        assert(f.grouping() == "\3\3");
+        assert(f.grouping() == us_grouping);
     }
     {
         Fwt f(LOCALE_en_US_UTF_8, 1);
-        assert(f.grouping() == "\3\3");
+        assert(f.grouping() == us_grouping);
     }
 #endif
 
     {
         Fnf f(LOCALE_fr_FR_UTF_8, 1);
         assert(f.grouping() == "\3");
     }
     {
         Fnt f(LOCALE_fr_FR_UTF_8, 1);
         assert(f.grouping() == "\3");
     }
 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
     {
         Fwf f(LOCALE_fr_FR_UTF_8, 1);
         assert(f.grouping() == "\3");
     }
     {
         Fwt f(LOCALE_fr_FR_UTF_8, 1);
         assert(f.grouping() == "\3");
     }
 #endif
 
+#ifdef _WIN32
+    std::string ru_grouping = "\3";
+#else
+    std::string ru_grouping = "\3\3";
+#endif
     {
         Fnf f(LOCALE_ru_RU_UTF_8, 1);
-        assert(f.grouping() == "\3\3");
+        assert(f.grouping() == ru_grouping);
     }
     {
         Fnt f(LOCALE_ru_RU_UTF_8, 1);
-        assert(f.grouping() == "\3\3");
+        assert(f.grouping() == ru_grouping);
     }
 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
     {
         Fwf f(LOCALE_ru_RU_UTF_8, 1);
-        assert(f.grouping() == "\3\3");
+        assert(f.grouping() == ru_grouping);
     }
     {
         Fwt f(LOCALE_ru_RU_UTF_8, 1);
-        assert(f.grouping() == "\3\3");
+        assert(f.grouping() == ru_grouping);
     }
 #endif
 
     {
         Fnf f(LOCALE_zh_CN_UTF_8, 1);
         assert(f.grouping() == "\3");
     }
     {

libcxx/test/std/localization/locale.categories/facet.numpunct/locale.numpunct.byname/grouping.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // NetBSD does not support LC_NUMERIC at the moment
 // XFAIL: netbsd
 
-// XFAIL: LIBCXX-WINDOWS-FIXME
 // XFAIL: LIBCXX-AIX-FIXME
 
 // REQUIRES: locale.en_US.UTF-8
 // REQUIRES: locale.fr_FR.UTF-8
 
 // <locale>
 
 // template <class charT> class numpunct_byname;
#ifndef TEST_HAS_NO_WIDE_CHARACTERS
         }
 #endif
     }
     {
         std::locale l(LOCALE_en_US_UTF_8);
         {
             typedef char C;
             const std::numpunct<C>& np = std::use_facet<std::numpunct<C> >(l);
+#ifdef _WIN32
+            assert(np.grouping() == "\3");
+#else
             assert(np.grouping() == "\3\3");
+#endif
         }
 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
         {
             typedef wchar_t C;
             const std::numpunct<C>& np = std::use_facet<std::numpunct<C> >(l);
+#ifdef _WIN32
+            assert(np.grouping() == "\3");
+#else
             assert(np.grouping() == "\3\3");
+#endif
         }
 #endif
     }
     {
         std::locale l(LOCALE_fr_FR_UTF_8);
-#if defined(TEST_HAS_GLIBC)
+#if defined(TEST_HAS_GLIBC) || defined(_WIN32)
         const char* const group = "\3";
 #else
         const char* const group = "\x7f";
 #endif
         {
             typedef char C;
             const std::numpunct<C>& np = std::use_facet<std::numpunct<C> >(l);
             assert(np.grouping() ==  group);