New module 'duplocale'.

[gnulib.git] / lib / duplocale.c

diff --git a/lib/duplocale.c b/lib/duplocale.c
new file mode 100644 (file)
index 0000000..63d00d9
--- /dev/null
+++ b/lib/duplocale.c
@@ -0,0 +1,105 @@
+/* Duplicate a locale object.
+   Copyright (C) 2009 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2007.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <locale.h>
+
+#include <errno.h>
+#include <langinfo.h>
+#include <string.h>
+
+/* Work around an incorrect definition of the _NL_LOCALE_NAME macro in
+   glibc < 2.12.
+   See <http://sourceware.org/bugzilla/show_bug.cgi?id=10968>.  */
+#undef _NL_LOCALE_NAME
+#define _NL_LOCALE_NAME(category) _NL_ITEM ((category), _NL_ITEM_INDEX (-1))
+
+#define SIZEOF(a) (sizeof(a) / sizeof(a[0]))
+
+#undef duplocale
+
+locale_t
+rpl_duplocale (locale_t locale)
+{
+  /* Work around crash in the duplocale function in glibc < 2.12.
+     See <http://sourceware.org/bugzilla/show_bug.cgi?id=10969>.  */
+  if (locale == LC_GLOBAL_LOCALE)
+    {
+      /* Create a copy of the locale by fetching the name of each locale
+        category, starting with LC_CTYPE.  */
+      static struct { int cat; int mask; } categories[] =
+       {
+           { LC_NUMERIC,        LC_NUMERIC_MASK },
+           { LC_TIME,           LC_TIME_MASK },
+           { LC_COLLATE,        LC_COLLATE_MASK },
+           { LC_MONETARY,       LC_MONETARY_MASK },
+           { LC_MESSAGES,       LC_MESSAGES_MASK }
+#ifdef LC_PAPER
+         , { LC_PAPER,          LC_PAPER_MASK }
+#endif
+#ifdef LC_NAME
+         , { LC_NAME,           LC_NAME_MASK }
+#endif
+#ifdef LC_ADDRESS
+         , { LC_ADDRESS,        LC_ADDRESS_MASK }
+#endif
+#ifdef LC_TELEPHONE
+         , { LC_TELEPHONE,      LC_TELEPHONE_MASK }
+#endif
+#ifdef LC_MEASUREMENT
+         , { LC_MEASUREMENT,    LC_MEASUREMENT_MASK }
+#endif
+#ifdef LC_IDENTIFICATION
+         , { LC_IDENTIFICATION, LC_IDENTIFICATION_MASK }
+#endif
+       };
+      const char *base_name = nl_langinfo (_NL_LOCALE_NAME (LC_CTYPE));
+      locale_t base_copy = newlocale (LC_ALL_MASK, base_name, NULL);
+      unsigned int i;
+
+      if (base_copy == NULL)
+       return NULL;
+
+      for (i = 0; i < SIZEOF (categories); i++)
+       {
+         int category = categories[i].cat;
+         int category_mask = categories[i].mask;
+         const char *name = nl_langinfo (_NL_LOCALE_NAME (category));
+         if (strcmp (name, base_name) != 0)
+           {
+             locale_t copy = newlocale (category_mask, name, base_copy);
+             if (copy == NULL)
+               {
+                 int saved_errno = errno;
+                 freelocale (base_copy);
+                 errno = saved_errno;
+                 return NULL;
+               }
+             /* No need to call freelocale (base_copy) if copy != base_copy;
+                the newlocale function already takes care of doing it.  */
+             base_copy = copy;
+           }
+       }
+
+      return base_copy;
+    }
+
+  return duplocale (locale);
+}