add _NL_LOCALE_NAME extension to nl_langinfo
since setlocale(cat, NULL) is required to return the setting for the
global locale, there is no standard mechanism to obtain the name of
the currently active thread-local locale set by uselocale. this makes
it impossible for application/library software to load appropriate
translations, etc. unless using the gettext implementation provided by
libc, which has privileged access to libc internals.
to fill this gap, glibc introduced the _NL_LOCALE_NAME macro which can
be used with nl_langinfo to obtain the name. GNU gettext/gnulib code
already use this functionality on glibc, and can easily be adapted to
make use of it on non-glibc systems if it's available; for other
systems they poke at locale implementation internals, which we want to
avoid. this patch provides a compatible interface to the one glibc
introduced.
diff --git a/include/langinfo.h b/include/langinfo.h
index 2153c42..519c061 100644
--- a/include/langinfo.h
+++ b/include/langinfo.h
@@ -77,6 +77,12 @@
#define YESEXPR 0x50000
#define NOEXPR 0x50001
+#define _NL_LOCALE_NAME(cat) (((cat)<<16) | 0xffff)
+
+#if defined(_GNU_SOURCE)
+#define NL_LOCALE_NAME(cat) _NL_LOCALE_NAME(cat)
+#endif
+
#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
#define YESSTR 0x50002
#define NOSTR 0x50003
diff --git a/src/locale/langinfo.c b/src/locale/langinfo.c
index b2c8569..b16caf4 100644
--- a/src/locale/langinfo.c
+++ b/src/locale/langinfo.c
@@ -34,6 +34,10 @@
const char *str;
if (item == CODESET) return MB_CUR_MAX==1 ? "ASCII" : "UTF-8";
+
+ /* _NL_LOCALE_NAME extension */
+ if (idx == 65535 && cat < LC_ALL)
+ return loc->cat[cat] ? (char *)loc->cat[cat]->name : "C";
switch (cat) {
case LC_NUMERIC:
