From 18f05ac59765d532823d48c061d0dcac7c55007e Mon Sep 17 00:00:00 2001
From: Bruno Haible <bruno@clisp.org>
Date: Thu, 9 Jan 2020 02:00:19 +0100
Subject: [PATCH 3/4] c32rtomb: Add tests.

* tests/test-c32rtomb.c: New file, based on tests/test-wcrtomb.c.
* tests/test-c32rtomb.sh: New file, based on tests/test-wcrtomb.sh.
* tests/test-c32rtomb-w32.c: New file, based on
tests/test-wcrtomb-w32.c.
* tests/test-c32rtomb-w32-1.sh: New file, based on
tests/test-wcrtomb-w32-1.sh.
* tests/test-c32rtomb-w32-2.sh: New file, based on
tests/test-wcrtomb-w32-2.sh.
* tests/test-c32rtomb-w32-3.sh: New file, based on
tests/test-wcrtomb-w32-3.sh.
* tests/test-c32rtomb-w32-4.sh: New file, based on
tests/test-wcrtomb-w32-4.sh.
* tests/test-c32rtomb-w32-5.sh: New file, based on
tests/test-wcrtomb-w32-5.sh.
* tests/test-c32rtomb-w32-6.sh: New file, based on
tests/test-wcrtomb-w32-6.sh.
* tests/test-c32rtomb-w32-7.sh: New file, based on
tests/test-wcrtomb-w32-7.sh.
* modules/c32rtomb-tests: New file.
---
 ChangeLog                    |  21 +++
 modules/c32rtomb-tests       |  43 ++++++
 tests/test-c32rtomb-w32-1.sh |   4 +
 tests/test-c32rtomb-w32-2.sh |   4 +
 tests/test-c32rtomb-w32-3.sh |   4 +
 tests/test-c32rtomb-w32-4.sh |   4 +
 tests/test-c32rtomb-w32-5.sh |   4 +
 tests/test-c32rtomb-w32-6.sh |   4 +
 tests/test-c32rtomb-w32-7.sh |   4 +
 tests/test-c32rtomb-w32.c    | 349 +++++++++++++++++++++++++++++++++++++++++++
 tests/test-c32rtomb.c        | 170 +++++++++++++++++++++
 tests/test-c32rtomb.sh       |  39 +++++
 12 files changed, 650 insertions(+)
 create mode 100644 modules/c32rtomb-tests
 create mode 100755 tests/test-c32rtomb-w32-1.sh
 create mode 100755 tests/test-c32rtomb-w32-2.sh
 create mode 100755 tests/test-c32rtomb-w32-3.sh
 create mode 100755 tests/test-c32rtomb-w32-4.sh
 create mode 100755 tests/test-c32rtomb-w32-5.sh
 create mode 100755 tests/test-c32rtomb-w32-6.sh
 create mode 100755 tests/test-c32rtomb-w32-7.sh
 create mode 100644 tests/test-c32rtomb-w32.c
 create mode 100644 tests/test-c32rtomb.c
 create mode 100755 tests/test-c32rtomb.sh

diff --git a/ChangeLog b/ChangeLog
index 3ad99ff..c303d41 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,26 @@
 2020-01-08  Bruno Haible  <bruno@clisp.org>
 
+	c32rtomb: Add tests.
+	* tests/test-c32rtomb.c: New file, based on tests/test-wcrtomb.c.
+	* tests/test-c32rtomb.sh: New file, based on tests/test-wcrtomb.sh.
+	* tests/test-c32rtomb-w32.c: New file, based on
+	tests/test-wcrtomb-w32.c.
+	* tests/test-c32rtomb-w32-1.sh: New file, based on
+	tests/test-wcrtomb-w32-1.sh.
+	* tests/test-c32rtomb-w32-2.sh: New file, based on
+	tests/test-wcrtomb-w32-2.sh.
+	* tests/test-c32rtomb-w32-3.sh: New file, based on
+	tests/test-wcrtomb-w32-3.sh.
+	* tests/test-c32rtomb-w32-4.sh: New file, based on
+	tests/test-wcrtomb-w32-4.sh.
+	* tests/test-c32rtomb-w32-5.sh: New file, based on
+	tests/test-wcrtomb-w32-5.sh.
+	* tests/test-c32rtomb-w32-6.sh: New file, based on
+	tests/test-wcrtomb-w32-6.sh.
+	* tests/test-c32rtomb-w32-7.sh: New file, based on
+	tests/test-wcrtomb-w32-7.sh.
+	* modules/c32rtomb-tests: New file.
+
 	c32rtomb: New module.
 	* lib/uchar.in.h (c32rtomb): New declaration.
 	* lib/c32rtomb.c: New file, based on lib/unistr/u8-uctomb-aux.c.
diff --git a/modules/c32rtomb-tests b/modules/c32rtomb-tests
new file mode 100644
index 0000000..a8d2bee
--- /dev/null
+++ b/modules/c32rtomb-tests
@@ -0,0 +1,43 @@
+Files:
+tests/test-c32rtomb.sh
+tests/test-c32rtomb.c
+tests/test-c32rtomb-w32-1.sh
+tests/test-c32rtomb-w32-2.sh
+tests/test-c32rtomb-w32-3.sh
+tests/test-c32rtomb-w32-4.sh
+tests/test-c32rtomb-w32-5.sh
+tests/test-c32rtomb-w32-6.sh
+tests/test-c32rtomb-w32-7.sh
+tests/test-c32rtomb-w32.c
+tests/signature.h
+tests/macros.h
+m4/locale-fr.m4
+m4/locale-ja.m4
+m4/locale-zh.m4
+m4/codeset.m4
+
+Depends-on:
+btoc32
+mbrtoc32
+setlocale
+localcharset
+
+configure.ac:
+gt_LOCALE_FR
+gt_LOCALE_FR_UTF8
+gt_LOCALE_JA
+gt_LOCALE_ZH_CN
+
+Makefile.am:
+TESTS += \
+  test-c32rtomb.sh \
+  test-c32rtomb-w32-1.sh test-c32rtomb-w32-2.sh test-c32rtomb-w32-3.sh \
+  test-c32rtomb-w32-4.sh test-c32rtomb-w32-5.sh test-c32rtomb-w32-6.sh \
+  test-c32rtomb-w32-7.sh
+TESTS_ENVIRONMENT += \
+  LOCALE_FR='@LOCALE_FR@' \
+  LOCALE_FR_UTF8='@LOCALE_FR_UTF8@' \
+  LOCALE_JA='@LOCALE_JA@' \
+  LOCALE_ZH_CN='@LOCALE_ZH_CN@'
+check_PROGRAMS += test-c32rtomb test-c32rtomb-w32
+test_c32rtomb_LDADD = $(LDADD) $(LIB_SETLOCALE)
diff --git a/tests/test-c32rtomb-w32-1.sh b/tests/test-c32rtomb-w32-1.sh
new file mode 100755
index 0000000..e797d0e
--- /dev/null
+++ b/tests/test-c32rtomb-w32-1.sh
@@ -0,0 +1,4 @@
+#!/bin/sh
+
+# Test a CP1252 locale.
+${CHECKER} ./test-c32rtomb-w32${EXEEXT} French_France 1252
diff --git a/tests/test-c32rtomb-w32-2.sh b/tests/test-c32rtomb-w32-2.sh
new file mode 100755
index 0000000..1b63d47
--- /dev/null
+++ b/tests/test-c32rtomb-w32-2.sh
@@ -0,0 +1,4 @@
+#!/bin/sh
+
+# Test a CP1256 locale.
+${CHECKER} ./test-c32rtomb-w32${EXEEXT} "Arabic_Saudi Arabia" 1256
diff --git a/tests/test-c32rtomb-w32-3.sh b/tests/test-c32rtomb-w32-3.sh
new file mode 100755
index 0000000..ff59a87
--- /dev/null
+++ b/tests/test-c32rtomb-w32-3.sh
@@ -0,0 +1,4 @@
+#!/bin/sh
+
+# Test a CP932 locale.
+${CHECKER} ./test-c32rtomb-w32${EXEEXT} Japanese_Japan 932
diff --git a/tests/test-c32rtomb-w32-4.sh b/tests/test-c32rtomb-w32-4.sh
new file mode 100755
index 0000000..3cf3406
--- /dev/null
+++ b/tests/test-c32rtomb-w32-4.sh
@@ -0,0 +1,4 @@
+#!/bin/sh
+
+# Test a CP950 locale.
+${CHECKER} ./test-c32rtomb-w32${EXEEXT} Chinese_Taiwan 950
diff --git a/tests/test-c32rtomb-w32-5.sh b/tests/test-c32rtomb-w32-5.sh
new file mode 100755
index 0000000..2174c0b
--- /dev/null
+++ b/tests/test-c32rtomb-w32-5.sh
@@ -0,0 +1,4 @@
+#!/bin/sh
+
+# Test a CP936 locale.
+${CHECKER} ./test-c32rtomb-w32${EXEEXT} Chinese_China 936
diff --git a/tests/test-c32rtomb-w32-6.sh b/tests/test-c32rtomb-w32-6.sh
new file mode 100755
index 0000000..b7e77b2
--- /dev/null
+++ b/tests/test-c32rtomb-w32-6.sh
@@ -0,0 +1,4 @@
+#!/bin/sh
+
+# Test a GB18030 locale.
+${CHECKER} ./test-c32rtomb-w32${EXEEXT} Chinese_China 54936
diff --git a/tests/test-c32rtomb-w32-7.sh b/tests/test-c32rtomb-w32-7.sh
new file mode 100755
index 0000000..3c0f3db
--- /dev/null
+++ b/tests/test-c32rtomb-w32-7.sh
@@ -0,0 +1,4 @@
+#!/bin/sh
+
+# Test some UTF-8 locales.
+${CHECKER} ./test-c32rtomb-w32${EXEEXT} French_France Japanese_Japan Chinese_Taiwan Chinese_China 65001
diff --git a/tests/test-c32rtomb-w32.c b/tests/test-c32rtomb-w32.c
new file mode 100644
index 0000000..18630c7
--- /dev/null
+++ b/tests/test-c32rtomb-w32.c
@@ -0,0 +1,349 @@
+/* Test of conversion of wide character to multibyte character.
+   Copyright (C) 2008-2020 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 <https://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+#include <uchar.h>
+
+#include <locale.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "localcharset.h"
+#include "macros.h"
+
+#if defined _WIN32 && !defined __CYGWIN__
+
+static int
+test_one_locale (const char *name, int codepage)
+{
+  char buf[64];
+  size_t ret;
+
+# if 1
+  /* Portable code to set the locale.  */
+  {
+    char name_with_codepage[1024];
+
+    sprintf (name_with_codepage, "%s.%d", name, codepage);
+
+    /* Set the locale.  */
+    if (setlocale (LC_ALL, name_with_codepage) == NULL)
+      return 77;
+  }
+# else
+  /* Hacky way to set a locale.codepage combination that setlocale() refuses
+     to set.  */
+  {
+    /* Codepage of the current locale, set with setlocale().
+       Not necessarily the same as GetACP().  */
+    extern __declspec(dllimport) unsigned int __lc_codepage;
+
+    /* Set the locale.  */
+    if (setlocale (LC_ALL, name) == NULL)
+      return 77;
+
+    /* Clobber the codepage and MB_CUR_MAX, both set by setlocale().  */
+    __lc_codepage = codepage;
+    switch (codepage)
+      {
+      case 1252:
+      case 1256:
+        MB_CUR_MAX = 1;
+        break;
+      case 932:
+      case 950:
+      case 936:
+        MB_CUR_MAX = 2;
+        break;
+      case 54936:
+      case 65001:
+        MB_CUR_MAX = 4;
+        break;
+      }
+
+    /* Test whether the codepage is really available.  */
+    {
+      mbstate_t state;
+      wchar_t wc;
+
+      memset (&state, '\0', sizeof (mbstate_t));
+      if (mbrtowc (&wc, " ", 1, &state) == (size_t)(-1))
+        return 77;
+    }
+  }
+# endif
+
+  /* Test NUL character.  */
+  {
+    buf[0] = 'x';
+    ret = c32rtomb (buf, 0, NULL);
+    ASSERT (ret == 1);
+    ASSERT (buf[0] == '\0');
+  }
+
+  /* Test single bytes.  */
+  {
+    int c;
+
+    for (c = 0; c < 0x100; c++)
+      switch (c)
+        {
+        case '\t': case '\v': case '\f':
+        case ' ': case '!': case '"': case '#': case '%':
+        case '&': case '\'': case '(': case ')': case '*':
+        case '+': case ',': case '-': case '.': case '/':
+        case '0': case '1': case '2': case '3': case '4':
+        case '5': case '6': case '7': case '8': case '9':
+        case ':': case ';': case '<': case '=': case '>':
+        case '?':
+        case 'A': case 'B': case 'C': case 'D': case 'E':
+        case 'F': case 'G': case 'H': case 'I': case 'J':
+        case 'K': case 'L': case 'M': case 'N': case 'O':
+        case 'P': case 'Q': case 'R': case 'S': case 'T':
+        case 'U': case 'V': case 'W': case 'X': case 'Y':
+        case 'Z':
+        case '[': case '\\': case ']': case '^': case '_':
+        case 'a': case 'b': case 'c': case 'd': case 'e':
+        case 'f': case 'g': case 'h': case 'i': case 'j':
+        case 'k': case 'l': case 'm': case 'n': case 'o':
+        case 'p': case 'q': case 'r': case 's': case 't':
+        case 'u': case 'v': case 'w': case 'x': case 'y':
+        case 'z': case '{': case '|': case '}': case '~':
+          /* c is in the ISO C "basic character set".  */
+          ret = c32rtomb (buf, btoc32 (c), NULL);
+          ASSERT (ret == 1);
+          ASSERT (buf[0] == (char) c);
+          break;
+        }
+  }
+
+  /* Test special calling convention, passing a NULL pointer.  */
+  {
+    ret = c32rtomb (NULL, '\0', NULL);
+    ASSERT (ret == 1);
+    ret = c32rtomb (NULL, btoc32 ('x'), NULL);
+    ASSERT (ret == 1);
+  }
+
+  switch (codepage)
+    {
+    case 1252:
+      /* Locale encoding is CP1252, an extension of ISO-8859-1.  */
+      {
+        /* Convert "B\374\337er": "Büßer" */
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x00FC, NULL);
+        ASSERT (ret == 1);
+        ASSERT (memcmp (buf, "\374", 1) == 0);
+        ASSERT (buf[1] == 'x');
+
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x00DF, NULL);
+        ASSERT (ret == 1);
+        ASSERT (memcmp (buf, "\337", 1) == 0);
+        ASSERT (buf[1] == 'x');
+      }
+      return 0;
+
+    case 1256:
+      /* Locale encoding is CP1256, not the same as ISO-8859-6.  */
+      {
+        /* Convert "x\302\341\346y": "xآلوy" */
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x0622, NULL);
+        ASSERT (ret == 1);
+        ASSERT (memcmp (buf, "\302", 1) == 0);
+        ASSERT (buf[1] == 'x');
+
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x0644, NULL);
+        ASSERT (ret == 1);
+        ASSERT (memcmp (buf, "\341", 1) == 0);
+        ASSERT (buf[1] == 'x');
+
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x0648, NULL);
+        ASSERT (ret == 1);
+        ASSERT (memcmp (buf, "\346", 1) == 0);
+        ASSERT (buf[1] == 'x');
+      }
+      return 0;
+
+    case 932:
+      /* Locale encoding is CP932, similar to Shift_JIS.  */
+      {
+        /* Convert "<\223\372\226\173\214\352>": "<日本語>" */
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x65E5, NULL);
+        ASSERT (ret == 2);
+        ASSERT (memcmp (buf, "\223\372", 2) == 0);
+        ASSERT (buf[2] == 'x');
+
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x672C, NULL);
+        ASSERT (ret == 2);
+        ASSERT (memcmp (buf, "\226\173", 2) == 0);
+        ASSERT (buf[2] == 'x');
+
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x8A9E, NULL);
+        ASSERT (ret == 2);
+        ASSERT (memcmp (buf, "\214\352", 2) == 0);
+        ASSERT (buf[2] == 'x');
+      }
+      return 0;
+
+    case 950:
+      /* Locale encoding is CP950, similar to Big5.  */
+      {
+        /* Convert "<\244\351\245\273\273\171>": "<日本語>" */
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x65E5, NULL);
+        ASSERT (ret == 2);
+        ASSERT (memcmp (buf, "\244\351", 2) == 0);
+        ASSERT (buf[2] == 'x');
+
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x672C, NULL);
+        ASSERT (ret == 2);
+        ASSERT (memcmp (buf, "\245\273", 2) == 0);
+        ASSERT (buf[2] == 'x');
+
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x8A9E, NULL);
+        ASSERT (ret == 2);
+        ASSERT (memcmp (buf, "\273\171", 2) == 0);
+        ASSERT (buf[2] == 'x');
+      }
+      return 0;
+
+    case 936:
+      /* Locale encoding is CP936 = GBK, an extension of GB2312.  */
+      {
+        /* Convert "<\310\325\261\276\325\132>": "<日本語>" */
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x65E5, NULL);
+        ASSERT (ret == 2);
+        ASSERT (memcmp (buf, "\310\325", 2) == 0);
+        ASSERT (buf[2] == 'x');
+
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x672C, NULL);
+        ASSERT (ret == 2);
+        ASSERT (memcmp (buf, "\261\276", 2) == 0);
+        ASSERT (buf[2] == 'x');
+
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x8A9E, NULL);
+        ASSERT (ret == 2);
+        ASSERT (memcmp (buf, "\325\132", 2) == 0);
+        ASSERT (buf[2] == 'x');
+      }
+      return 0;
+
+    case 54936:
+      /* Locale encoding is CP54936 = GB18030.  */
+      if (strcmp (locale_charset (), "GB18030") != 0)
+        return 77;
+      {
+        /* Convert "s\250\271\201\060\211\070\224\071\375\067!"; "süß😋!" */
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x00FC, NULL);
+        ASSERT (ret == 2);
+        ASSERT (memcmp (buf, "\250\271", 2) == 0);
+        ASSERT (buf[2] == 'x');
+
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x00DF, NULL);
+        ASSERT (ret == 4);
+        ASSERT (memcmp (buf, "\201\060\211\070", 4) == 0);
+        ASSERT (buf[4] == 'x');
+
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x1F60B, NULL);
+        ASSERT (ret == 4);
+        ASSERT (memcmp (buf, "\224\071\375\067", 4) == 0);
+        ASSERT (buf[4] == 'x');
+      }
+      return 0;
+
+    case 65001:
+      /* Locale encoding is CP65001 = UTF-8.  */
+      if (strcmp (locale_charset (), "UTF-8") != 0)
+        return 77;
+      {
+        /* Convert "s\303\274\303\237\360\237\230\213!"; "süß😋!" */
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x00FC, NULL);
+        ASSERT (ret == 2);
+        ASSERT (memcmp (buf, "\303\274", 2) == 0);
+        ASSERT (buf[2] == 'x');
+
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x00DF, NULL);
+        ASSERT (ret == 2);
+        ASSERT (memcmp (buf, "\303\237", 2) == 0);
+        ASSERT (buf[2] == 'x');
+
+        memset (buf, 'x', 8);
+        ret = c32rtomb (buf, 0x1F60B, NULL);
+        ASSERT (ret == 4);
+        ASSERT (memcmp (buf, "\360\237\230\213", 4) == 0);
+        ASSERT (buf[4] == 'x');
+      }
+      return 0;
+
+    default:
+      return 1;
+    }
+}
+
+int
+main (int argc, char *argv[])
+{
+  int codepage = atoi (argv[argc - 1]);
+  int result;
+  int i;
+
+  result = 77;
+  for (i = 1; i < argc - 1; i++)
+    {
+      int ret = test_one_locale (argv[i], codepage);
+
+      if (ret != 77)
+        result = ret;
+    }
+
+  if (result == 77)
+    {
+      fprintf (stderr, "Skipping test: found no locale with codepage %d\n",
+               codepage);
+    }
+  return result;
+}
+
+#else
+
+int
+main (int argc, char *argv[])
+{
+  fputs ("Skipping test: not a native Windows system\n", stderr);
+  return 77;
+}
+
+#endif
diff --git a/tests/test-c32rtomb.c b/tests/test-c32rtomb.c
new file mode 100644
index 0000000..108efe3
--- /dev/null
+++ b/tests/test-c32rtomb.c
@@ -0,0 +1,170 @@
+/* Test of conversion of wide character to multibyte character.
+   Copyright (C) 2008-2020 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 <https://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2008.  */
+
+#include <config.h>
+
+#include <uchar.h>
+
+#include "signature.h"
+SIGNATURE_CHECK (c32rtomb, size_t, (char *, char32_t, mbstate_t *));
+
+#include <locale.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "macros.h"
+
+/* Check the multibyte character s[0..n-1].  */
+static void
+check_character (const char *s, size_t n)
+{
+  mbstate_t state;
+  char32_t wc;
+  char buf[64];
+  int iret;
+  size_t ret;
+
+  memset (&state, '\0', sizeof (mbstate_t));
+  wc = (char32_t) 0xBADFACE;
+  iret = mbrtoc32 (&wc, s, n, &state);
+  ASSERT (iret == n);
+
+  ret = c32rtomb (buf, wc, NULL);
+  ASSERT (ret == n);
+  ASSERT (memcmp (buf, s, n) == 0);
+
+  /* Test special calling convention, passing a NULL pointer.  */
+  ret = c32rtomb (NULL, wc, NULL);
+  ASSERT (ret == 1);
+}
+
+int
+main (int argc, char *argv[])
+{
+  char buf[64];
+  size_t ret;
+
+  /* configure should already have checked that the locale is supported.  */
+  if (setlocale (LC_ALL, "") == NULL)
+    return 1;
+
+  /* Test NUL character.  */
+  {
+    buf[0] = 'x';
+    ret = c32rtomb (buf, 0, NULL);
+    ASSERT (ret == 1);
+    ASSERT (buf[0] == '\0');
+  }
+
+  /* Test single bytes.  */
+  {
+    int c;
+
+    for (c = 0; c < 0x100; c++)
+      switch (c)
+        {
+        case '\t': case '\v': case '\f':
+        case ' ': case '!': case '"': case '#': case '%':
+        case '&': case '\'': case '(': case ')': case '*':
+        case '+': case ',': case '-': case '.': case '/':
+        case '0': case '1': case '2': case '3': case '4':
+        case '5': case '6': case '7': case '8': case '9':
+        case ':': case ';': case '<': case '=': case '>':
+        case '?':
+        case 'A': case 'B': case 'C': case 'D': case 'E':
+        case 'F': case 'G': case 'H': case 'I': case 'J':
+        case 'K': case 'L': case 'M': case 'N': case 'O':
+        case 'P': case 'Q': case 'R': case 'S': case 'T':
+        case 'U': case 'V': case 'W': case 'X': case 'Y':
+        case 'Z':
+        case '[': case '\\': case ']': case '^': case '_':
+        case 'a': case 'b': case 'c': case 'd': case 'e':
+        case 'f': case 'g': case 'h': case 'i': case 'j':
+        case 'k': case 'l': case 'm': case 'n': case 'o':
+        case 'p': case 'q': case 'r': case 's': case 't':
+        case 'u': case 'v': case 'w': case 'x': case 'y':
+        case 'z': case '{': case '|': case '}': case '~':
+          /* c is in the ISO C "basic character set".  */
+          ret = c32rtomb (buf, btoc32 (c), NULL);
+          ASSERT (ret == 1);
+          ASSERT (buf[0] == (char) c);
+          break;
+        }
+  }
+
+  /* Test special calling convention, passing a NULL pointer.  */
+  {
+    ret = c32rtomb (NULL, '\0', NULL);
+    ASSERT (ret == 1);
+    ret = c32rtomb (NULL, btoc32 ('x'), NULL);
+    ASSERT (ret == 1);
+  }
+
+  if (argc > 1)
+    switch (argv[1][0])
+      {
+      case '1':
+        /* Locale encoding is ISO-8859-1 or ISO-8859-15.  */
+        {
+          const char input[] = "B\374\337er"; /* "Büßer" */
+
+          check_character (input + 1, 1);
+          check_character (input + 2, 1);
+        }
+        return 0;
+
+      case '2':
+        /* Locale encoding is UTF-8.  */
+        {
+          const char input[] = "s\303\274\303\237\360\237\230\213!"; /* "süß😋!" */
+
+          check_character (input + 1, 2);
+          check_character (input + 3, 2);
+          check_character (input + 5, 4);
+        }
+        return 0;
+
+      case '3':
+        /* Locale encoding is EUC-JP.  */
+        {
+          const char input[] = "<\306\374\313\334\270\354>"; /* "<日本語>" */
+
+          check_character (input + 1, 2);
+          check_character (input + 3, 2);
+          check_character (input + 5, 2);
+        }
+        return 0;
+
+      case '4':
+        /* Locale encoding is GB18030.  */
+        {
+          const char input[] = "s\250\271\201\060\211\070\224\071\375\067!"; /* "süß😋!" */
+
+          check_character (input + 1, 2);
+          check_character (input + 3, 4);
+          check_character (input + 7, 4);
+        }
+        return 0;
+
+      case '5':
+        /* C locale; tested above.  */
+        return 0;
+      }
+
+  return 1;
+}
diff --git a/tests/test-c32rtomb.sh b/tests/test-c32rtomb.sh
new file mode 100755
index 0000000..2899297
--- /dev/null
+++ b/tests/test-c32rtomb.sh
@@ -0,0 +1,39 @@
+#!/bin/sh
+
+# Test in an ISO-8859-1 or ISO-8859-15 locale.
+: ${LOCALE_FR=fr_FR}
+if test $LOCALE_FR != none; then
+  LC_ALL=$LOCALE_FR \
+  ${CHECKER} ./test-c32rtomb${EXEEXT} 1 \
+  || exit 1
+fi
+
+# Test whether a specific UTF-8 locale is installed.
+: ${LOCALE_FR_UTF8=fr_FR.UTF-8}
+if test $LOCALE_FR_UTF8 != none; then
+  LC_ALL=$LOCALE_FR_UTF8 \
+  ${CHECKER} ./test-c32rtomb${EXEEXT} 2 \
+  || exit 1
+fi
+
+# Test whether a specific EUC-JP locale is installed.
+: ${LOCALE_JA=ja_JP}
+if test $LOCALE_JA != none; then
+  LC_ALL=$LOCALE_JA \
+  ${CHECKER} ./test-c32rtomb${EXEEXT} 3 \
+  || exit 1
+fi
+
+# Test whether a specific GB18030 locale is installed.
+: ${LOCALE_ZH_CN=zh_CN.GB18030}
+if test $LOCALE_ZH_CN != none; then
+  LC_ALL=$LOCALE_ZH_CN \
+  ${CHECKER} ./test-c32rtomb${EXEEXT} 4 \
+  || exit 1
+fi
+
+# Test in the POSIX locale.
+LC_ALL=C     ${CHECKER} ./test-c32rtomb${EXEEXT} 5 || exit 1
+LC_ALL=POSIX ${CHECKER} ./test-c32rtomb${EXEEXT} 5 || exit 1
+
+exit 0
-- 
2.7.4