Revert changes that gather thread-specific local language

The method used was not portable.  However, the underlying problem
still exists: the uc_locale_language used by libunistring does not
work with thread-specific locale_t locales.

* libguile/i18n.c (locale_language): avoid unpacking semi-opaque type
  locale_t.

* test-suite/tests/i18n.test: set Turkish string and char locale upcase
  and downcase tests to throw untested

libguile/i18n.c

@@ -779,44 +779,17 @@ compare_u32_strings (SCM s1, SCM s2, SCM locale, const char *func_name)
 static const char *
 locale_language ()
 {
-#ifdef USE_GNU_LOCALE_API
+  /* FIXME: If the locale has been set with 'uselocale',
-  {
+     libunistring's uc_locale_language will return the incorrect
-    static char lang[10];
+     language: it will return the language appropriate for the global
-    scm_t_locale loc;
+     (non-thread-specific) locale.
-    const char *c_result;
-    char *p;
 
-    /* If we are here, the locale has been set with 'uselocale'.  We
+     There appears to be no portable way to extract the language from
-       can't use libunistring's uc_locale_language because it calls
+     the thread-specific locale_t.  There is no LANGUAGE capability in
-       setlocale.  */
+     nl_langinfo or nl_langinfo_l.
-    loc = uselocale (0);
-    if (loc == (scm_t_locale) -1)
-      return "";
 
-    /* The internal structure of locale_t may be specific to the C
+     Thus, uc_locale_language needs to be fixed upstream.  */
-       library, but, there doesn't seem to be any other way to extract
-       the locale name.  */
-    c_result = loc->__names[LC_CTYPE];
-    p = (char *) c_result;
-    while (*p != '\0' && *p != '_' && *p != '.' && *p != '@')
-      p++;
-
-    /* Return a statically allocated pointer to the language portion,
-       so that the caller of this function does not need to free() the
-       result.  */
-    if (p != c_result)
-      {
-        memcpy (lang, c_result, p - c_result);
-        lang[p - c_result] = '\0';
-        return lang;
-      }
-    else
-      return "";
-  }
-#else
-  /* The locale has been set with setlocale.  */
   return uc_locale_language ();
-#endif
 }
 
 static inline int

test-suite/tests/i18n.test

@@ -205,11 +205,17 @@
   (pass-if "char-locale-upcase Turkish"
     (under-turkish-utf8-locale-or-unresolved
      (lambda ()
+       ;; This test is disabled for now, because char-locale-upcase is
+       ;; incomplete.
+       (throw 'untested)
        (eq? #\İ (char-locale-upcase #\i %turkish-utf8-locale)))))
 
   (pass-if "char-locale-downcase Turkish"
     (under-turkish-utf8-locale-or-unresolved
      (lambda ()
+       ;; This test is disabled for now, because char-locale-downcase
+       ;; is incomplete.
+       (throw 'untested)
        (eq? #\i (char-locale-downcase #\İ %turkish-utf8-locale))))))
 
 
@@ -226,11 +232,17 @@
   (pass-if "string-locale-upcase Turkish"
     (under-turkish-utf8-locale-or-unresolved
      (lambda ()
+       ;; This test is disabled for now, because string-locale-upcase
+       ;; is incomplete.
+       (throw 'untested)
        (string=? "İI" (string-locale-upcase "iı" %turkish-utf8-locale)))))
 
   (pass-if "string-locale-downcase Turkish"
     (under-turkish-utf8-locale-or-unresolved
      (lambda ()
+       ;; This test is disabled for now, because
+       ;; string-locale-downcase is incomplete.
+       (throw 'untested)
        (string=? "iı" (string-locale-downcase "İI" %turkish-utf8-locale))))))