--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2007-03-04  Bruno Haible  <bruno@clisp.org>
 
+	* modules/vsnprintf-tests: New file.
+	* tests/test-vsnprintf.c: New file.
+
 	* modules/snprintf-tests: New file.
 	* tests/test-snprintf.c: New file.
 

new file mode 100644
--- /dev/null
+++ b/modules/vsnprintf-tests
@@ -0,0 +1,11 @@
+Files:
+tests/test-vsnprintf.c
+
+Depends-on:
+
+configure.ac:
+
+Makefile.am:
+TESTS += test-vsnprintf
+check_PROGRAMS += test-vsnprintf
+

new file mode 100644
--- /dev/null
+++ b/tests/test-vsnprintf.c
@@ -0,0 +1,73 @@
+/* Test of vsnprintf() function.
+   Copyright (C) 2007 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 2, 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, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2007.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdio.h>
+
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define ASSERT(expr) if (!(expr)) abort ();
+
+static int
+my_snprintf (char *buf, int size, const char *format, ...)
+{
+  va_list args;
+  int ret;
+
+  va_start (args, format);
+  ret = vsnprintf (buf, size, format, args);
+  va_end (args);
+  return ret;
+}
+
+int
+main (int argc, char *argv[])
+{
+  char buf[8];
+  int size;
+  int retval;
+
+  for (size = 0; size <= 8; size++)
+    {
+      memcpy (buf, "DEADBEEF", 8);
+      retval = my_snprintf (buf, size, "%d", 12345);
+      if (size < 6)
+	{
+	  ASSERT (retval < 0 || retval >= size);
+	  if (size > 0)
+	    {
+	      ASSERT (memcmp (buf, "12345", size - 1) == 0);
+	      ASSERT (buf[size - 1] == '\0' || buf[size - 1] == '0' + size);
+	    }
+	  ASSERT (memcmp (buf + size, "DEADBEEF" + size, 8 - size) == 0);
+	}
+      else
+	{
+	  ASSERT (retval == 5);
+	  ASSERT (memcmp (buf, "12345\0EF", 8) == 0);
+	}
+    }
+
+  return 0;
+}