Chris Jefferson spotted a problem with messages_base::catalog while getting libc++ to work on boost. The standard says this type must be an int. But this type is the key returned by the OS facility catopen. On OS X the type returned by catopen is void*, which doesn't fit into an int on 64 bit platforms. Chris suggested using ptrdiff_t instead of void*. It still isn't compliant with the standard, but chances are that this change will fix what is ailing boost. Chris also supplied the algorithm for distinguishing high-order pointers from error conditions. Thanks Chris.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@126462 91177308-0d34-0410-b5e6-96231b3b80d8

include/locale

@@ -3474,7 +3474,7 @@ extern template class money_put<wchar_t>;
 class _LIBCPP_VISIBLE messages_base
 {
 public:
-    typedef nl_catd catalog;
+    typedef ptrdiff_t catalog;
 
     _LIBCPP_ALWAYS_INLINE messages_base() {}
 };
@@ -3531,7 +3531,10 @@ template <class _CharT>
 typename messages<_CharT>::catalog
 messages<_CharT>::do_open(const basic_string<char>& __nm, const locale&) const
 {
-    return catopen(__nm.c_str(), NL_CAT_LOCALE);
+    catalog __cat = reinterpret_cast<catalog>(catopen(__nm.c_str(), NL_CAT_LOCALE));
+    if (__cat != -1)
+        __cat = static_cast<catalog>((static_cast<size_t>(__cat) >> 1));
+    return __cat;
 }
 
 template <class _CharT>
@@ -3543,7 +3546,10 @@ messages<_CharT>::do_get(catalog __c, int __set, int __msgid,
     __narrow_to_utf8<sizeof(char_type)*__CHAR_BIT__>()(back_inserter(__ndflt),
                                                        __dflt.c_str(),
                                                        __dflt.c_str() + __dflt.size());
-    char* __n = catgets(__c, __set, __msgid, __ndflt.c_str());
+    if (__c != -1)
+        __c <<= 1;
+    nl_catd __cat = reinterpret_cast<nl_catd>(__c);
+    char* __n = catgets(__cat, __set, __msgid, __ndflt.c_str());
     string_type __w;
     __widen_from_utf8<sizeof(char_type)*__CHAR_BIT__>()(back_inserter(__w),
                                                         __n, __n + strlen(__n));
@@ -3554,7 +3560,10 @@ template <class _CharT>
 void
 messages<_CharT>::do_close(catalog __c) const
 {
-    catclose(__c);
+    if (__c != -1)
+        __c <<= 1;
+    nl_catd __cat = reinterpret_cast<nl_catd>(__c);
+    catclose(__cat);
 }
 
 extern template class messages<char>;