--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2008-12-17  Bruno Haible  <bruno@clisp.org>
 
+	* modules/btowc-tests: New file.
+	* tests/test-btowc1.sh: New file.
+	* tests/test-btowc2.sh: New file.
+	* tests/test-btowc.c: New file.
+
 	New module 'btowc'.
 	* lib/wchar.in.h (btowc): New declaration.
 	* lib/btowc.c: New file.

new file mode 100644
--- /dev/null
+++ b/modules/btowc-tests
@@ -0,0 +1,18 @@
+Files:
+tests/test-btowc1.sh
+tests/test-btowc2.sh
+tests/test-btowc.c
+m4/locale-fr.m4
+m4/codeset.m4
+
+Depends-on:
+
+configure.ac:
+gt_LOCALE_FR
+gt_LOCALE_FR_UTF8
+
+Makefile.am:
+TESTS += test-btowc1.sh test-btowc2.sh
+TESTS_ENVIRONMENT += EXEEXT='@EXEEXT@' LOCALE_FR='@LOCALE_FR@' LOCALE_FR_UTF8='@LOCALE_FR_UTF8@'
+check_PROGRAMS += test-btowc
+

new file mode 100644
--- /dev/null
+++ b/tests/test-btowc.c
@@ -0,0 +1,71 @@
+/* Test of conversion of unibyte character to wide character.
+   Copyright (C) 2008 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>, 2008.  */
+
+#include <config.h>
+
+#include <wchar.h>
+
+#include <locale.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define ASSERT(expr) \
+  do									     \
+    {									     \
+      if (!(expr))							     \
+        {								     \
+          fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
+          fflush (stderr);						     \
+          abort ();							     \
+        }								     \
+    }									     \
+  while (0)
+
+int
+main (int argc, char *argv[])
+{
+  int c;
+
+  /* configure should already have checked that the locale is supported.  */
+  if (setlocale (LC_ALL, "") == NULL)
+    return 1;
+
+  ASSERT (btowc (EOF) == WEOF);
+
+  if (argc > 1)
+    switch (argv[1][0])
+      {
+      case '1':
+	/* Locale encoding is ISO-8859-1 or ISO-8859-15.  */
+	for (c = 0; c < 0x80; c++)
+	  ASSERT (btowc (c) == c);
+	for (c = 0xA0; c < 0x100; c++)
+	  ASSERT (btowc (c) != WEOF);
+	return 0;
+
+      case '2':
+	/* Locale encoding is UTF-8.  */
+	for (c = 0; c < 0x80; c++)
+	  ASSERT (btowc (c) == c);
+	for (c = 0x80; c < 0x100; c++)
+	  ASSERT (btowc (c) == WEOF);
+	return 0;
+      }
+
+  return 1;
+}

new file mode 100755
--- /dev/null
+++ b/tests/test-btowc1.sh
@@ -0,0 +1,15 @@
+#!/bin/sh
+
+# Test in an ISO-8859-1 or ISO-8859-15 locale.
+: ${LOCALE_FR=fr_FR}
+if test $LOCALE_FR = none; then
+  if test -f /usr/bin/localedef; then
+    echo "Skipping test: no traditional french locale is installed"
+  else
+    echo "Skipping test: no traditional french locale is supported"
+  fi
+  exit 77
+fi
+
+LC_ALL=$LOCALE_FR \
+./test-btowc${EXEEXT} 1

new file mode 100755
--- /dev/null
+++ b/tests/test-btowc2.sh
@@ -0,0 +1,15 @@
+#!/bin/sh
+
+# Test whether a specific UTF-8 locale is installed.
+: ${LOCALE_FR_UTF8=fr_FR.UTF-8}
+if test $LOCALE_FR_UTF8 = none; then
+  if test -f /usr/bin/localedef; then
+    echo "Skipping test: no french Unicode locale is installed"
+  else
+    echo "Skipping test: no french Unicode locale is supported"
+  fi
+  exit 77
+fi
+
+LC_ALL=$LOCALE_FR_UTF8 \
+./test-btowc${EXEEXT} 2