Fix setlocale() to conform to the ISO C and POSIX standards.

The below text is quoted from the latest POSIX draft:

: The values of locale categories shall be determined by a precedence
: order; the first condition met below determines the value:
:
: 1. If the LC_ALL environment variable is defined and is not null,
:    the value of LC_ALL shall be used.
: 2. If the LC_* environment variable (LC_COLLATE, LC_CTYPE, LC_MESSAGES,
:    LC_MONETARY, LC_NUMERIC, LC_TIME) is defined and is not null, the
:    value of the environment variable shall be used to initialize the
:    category that corresponds to the environment variable.
: 3. If the LANG environment variable is defined and is not null, the
:    value of the LANG environment variable shall be used.
: 4. If the LANG environment variable is not set or is set to the empty
:    string, the implementation-defined default locale shall be used.

The conditions 1 and 2 were interchanged, i.e., LC_* were looked first,
then LC_ALL, then LANG (note that LC_ALL and LANG were essentially the
same, providing the default, with LC_ALL taking precedence over LANG).
Now, LC_ALL and LANG serve the different purposes.  LC_ALL overrides
any LC_*, and LANG provides the default fallback.

Testcase:

/usr/bin/env LC_ALL=C LC_TIME=de_DE.ISO_8859-1 /bin/date

Should return date in the "C" locale format.

Inspired by:	date(1) reference page in the Draft

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/libc/locale/setlocale.c b/lib/libc/locale/setlocale.c
index ccae906..825a2fb 100644
--- a/lib/libc/locale/setlocale.c
+++ b/lib/libc/locale/setlocale.c
@@ -124,10 +124,10 @@ setlocale(category, locale)
 	 * Now go fill up new_categories from the locale argument
 	 */
 	if (!*locale) {
-		env = getenv(categories[category]);
+		env = getenv("LC_ALL");
 
 		if (category != LC_ALL && (!env || !*env))
-			env = getenv(categories[LC_ALL]);
+			env = getenv(categories[category]);
 
 		if (!env || !*env)
 			env = getenv("LANG");