Fix order of environment variables when getting system default locale

See https://svn.boost.org/trac10/ticket/13289
Closes boostorg#22

doc/locale_gen.txt

@@ -46,8 +46,8 @@ Of course we can also specify the locale manually
 -   Even if your application uses wide strings everywhere, you should specify the
     8-bit encoding to use for 8-bit stream IO operations like \c cout or \c fstream.
     \n
--   The default locale is defined by the environment variables \c LC_CTYPE , \c LC_ALL , and \c LANG
-    in that order (i.e. \c LC_CTYPE first and \c LANG last). On Windows, the library
+-   The default locale is defined by the environment variables \c LC_ALL , \c LC_CTYPE , and \c LANG
+    in that order (i.e. \c LC_ALL first and \c LANG last). On Windows, the library
     also queries the \c LOCALE_USER_DEFAULT option in the Win32 API when these variables
     are not set.
 

include/boost/locale/util.hpp

@@ -22,15 +22,14 @@ namespace boost { namespace locale {
 
         /// \brief Return default system locale name in POSIX format.
         ///
-        /// This function tries to detect the locale using, LC_CTYPE, LC_ALL and LANG environment
-        /// variables in this order and if all of them unset, in POSIX platforms it returns "C"
-        ///
-        /// On Windows additionally to check the above environment variables, this function
-        /// tries to creates locale name from ISO-339 and ISO-3199 country codes defined
-        /// for user default locale.
-        /// If \a use_utf8_on_windows is true it sets the encoding to UTF-8, otherwise, if system
-        /// locale supports ANSI code-page it defines the ANSI encoding like windows-1252, otherwise it fall-backs
-        /// to UTF-8 encoding if ANSI code-page is not available.
+        /// This function tries to detect the locale using LC_ALL, LC_CTYPE and LANG environment
+        /// variables in this order and if all of them are unset, on POSIX platforms it returns "C".
+        /// On Windows additionally to the above environment variables, this function
+        /// tries to create the locale name from ISO-339 and ISO-3199 country codes defined
+        /// for the users default locale.
+        /// If \a use_utf8_on_windows is true it sets the encoding to UTF-8,
+        /// otherwise, if the system locale supports ANSI codepages it defines the ANSI encoding, e.g. windows-1252,
+        /// otherwise (if ANSI codepage is not available) it uses UTF-8 encoding.
         BOOST_LOCALE_DECL
         std::string get_system_locale(bool use_utf8_on_windows = false);
 

src/boost/locale/util/default_locale.cpp

@@ -17,24 +17,24 @@
 #endif
 
 namespace boost { namespace locale { namespace util {
-    std::string get_system_locale(bool use_utf8)
+    std::string get_system_locale(bool use_utf8_on_windows)
     {
         const char* lang = 0;
-        if(!lang || !*lang)
-            lang = getenv("LC_CTYPE");
         if(!lang || !*lang)
             lang = getenv("LC_ALL");
+        if(!lang || !*lang)
+            lang = getenv("LC_CTYPE");
         if(!lang || !*lang)
             lang = getenv("LANG");
 #ifndef BOOST_LOCALE_USE_WIN32_API
-        (void)use_utf8; // not relevant for non-windows
+        (void)use_utf8_on_windows; // not relevant for non-windows
         if(!lang || !*lang)
             lang = "C";
         return lang;
 #else
-        if(lang && *lang) {
+        if(lang && *lang)
             return lang;
-        }
+
         char buf[10];
         if(GetLocaleInfoA(LOCALE_USER_DEFAULT, LOCALE_SISO639LANGNAME, buf, sizeof(buf)) == 0)
             return "C";
@@ -43,19 +43,18 @@ namespace boost { namespace locale { namespace util {
             lc_name += "_";
             lc_name += buf;
         }
-        if(!use_utf8) {
+        if(use_utf8_on_windows)
+            lc_name += ".UTF-8";
+        else {
             if(GetLocaleInfoA(LOCALE_USER_DEFAULT, LOCALE_IDEFAULTANSICODEPAGE, buf, sizeof(buf)) != 0) {
                 if(atoi(buf) == 0)
                     lc_name += ".UTF-8";
                 else {
                     lc_name += ".windows-";
                     lc_name += buf;
                 }
-            } else {
-                lc_name += "UTF-8";
-            }
-        } else {
-            lc_name += ".UTF-8";
+            } else
+                lc_name += ".UTF-8";
         }
         return lc_name;