tests: Don't depend on the exact locale name

[Bruno Haible]

The locale names that I hardcoded in some tests are not those present in
some systems. This patch fixes it.


2024-07-13  Bruno Haible  <br...@clisp.org>

        tests: Don't depend on the exact locale name.
        * tests/test-c-ctype.c: Include <stdlib.h>.
        (main): Test the return value of setlocale(). Try not only de_DE, but
        also de_DE.ISO-8859-1.
        * tests/test-vasnprintf-posix3.c (main): Try not only fa_IR.UTF-8, but
        also fa_IR.
        * tests/test-vasnwprintf-posix3.c (main): Likewise.

diff --git a/tests/test-c-ctype.c b/tests/test-c-ctype.c
index 898e79cc8a..7816543a72 100644
--- a/tests/test-c-ctype.c
+++ b/tests/test-c-ctype.c
@@ -23,6 +23,7 @@
 #include <ctype.h>
 #include <limits.h>
 #include <locale.h>
+#include <stdlib.h>
 
 #include "macros.h"
 
@@ -218,11 +219,16 @@ main ()
 
   test_all ();
 
-  setlocale (LC_ALL, "de_DE");
-  test_all ();
+  /* Run the tests in a German unibyte locale.  */
+  if ((setlocale (LC_ALL, "de_DE") != NULL
+       || setlocale (LC_ALL, "de_DE.ISO-8859-1") != NULL)
+      && MB_CUR_MAX == 1)
+    test_all ();
 
-  setlocale (LC_ALL, "ja_JP.EUC-JP");
-  test_all ();
+  /* Run the tests in a traditional Japanese locale.  */
+  if (setlocale (LC_ALL, "ja_JP.EUC-JP") != NULL
+      && MB_CUR_MAX == 2)
+    test_all ();
 
   return test_exit_status;
 }
diff --git a/tests/test-vasnprintf-posix3.c b/tests/test-vasnprintf-posix3.c
index 0db514c601..568bfa912e 100644
--- a/tests/test-vasnprintf-posix3.c
+++ b/tests/test-vasnprintf-posix3.c
@@ -79,7 +79,8 @@ main (int argc, char *argv[])
 {
 #if (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3)) && !defined 
__UCLIBC__
   /* Select a locale with Arabic 'outdigits'.  */
-  if (setlocale (LC_ALL, "fa_IR.UTF-8") == NULL)
+  if (setlocale (LC_ALL, "fa_IR.UTF-8") == NULL
+      && setlocale (LC_ALL, "fa_IR") == NULL)
     {
       fprintf (stderr, "Skipping test: no Iranian locale is installed\n");
       return 77;
diff --git a/tests/test-vasnwprintf-posix3.c b/tests/test-vasnwprintf-posix3.c
index f2ddc82660..53923bab77 100644
--- a/tests/test-vasnwprintf-posix3.c
+++ b/tests/test-vasnwprintf-posix3.c
@@ -83,7 +83,8 @@ main (int argc, char *argv[])
 {
 #if (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3)) && !defined 
__UCLIBC__
   /* Select a locale with Arabic 'outdigits'.  */
-  if (setlocale (LC_ALL, "fa_IR.UTF-8") == NULL)
+  if (setlocale (LC_ALL, "fa_IR.UTF-8") == NULL
+      && setlocale (LC_ALL, "fa_IR") == NULL)
     {
       fprintf (stderr, "Skipping test: no Iranian locale is installed\n");
       return 77;