--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,21 @@
+2011-06-06  Bruno Haible  <bruno@clisp.org>
+
+	spawn-pipe tests: Like the child program only against libc.
+	* tests/test-spawn-pipe-child.c: New file, extracted from
+	tests/test-spawn-pipe.c.
+	(main): Expect only one argument.
+	(is_open): New function, copied from tests/test-pipe.c.
+	* tests/test-spawn-pipe.c: Don't include <errno.h>.
+	(child_main): Remove function.
+	(test_pipe): Pass only one argument to the child program.
+	(main): Remove child process code. Expect the child program's name as
+	first argument.
+	* tests/test-spawn-pipe.sh: Pass the child program's name as first
+	argument.
+	* modules/spawn-pipe-tests (Files): Add tests/test-spawn-pipe-child.c.
+	(Makefile.am): Add test-spawn-pipe-child to check_PROGRAMS. Link
+	test-spawn-pipe-child against no libraries.
+
 2011-06-06  Bruno Haible  <bruno@clisp.org>
 
 	careadlinkat: Avoid mismatch between ssize_t and int.

--- a/modules/spawn-pipe-tests
+++ b/modules/spawn-pipe-tests
@@ -1,6 +1,7 @@
 Files:
 tests/test-spawn-pipe.sh
 tests/test-spawn-pipe.c
+tests/test-spawn-pipe-child.c
 tests/macros.h
 
 Depends-on:
@@ -10,5 +11,9 @@
 
 Makefile.am:
 TESTS += test-spawn-pipe.sh
-check_PROGRAMS += test-spawn-pipe
+check_PROGRAMS += test-spawn-pipe test-spawn-pipe-child
 test_spawn_pipe_LDADD = $(LDADD) @LIBINTL@
+# The test-spawn-pipe-child program must be a real executable, not a libtool
+# wrapper script, and should link against as few libraries as possible.
+# Therefore don't link it against any libraries other than -lc.
+test_spawn_pipe_child_LDADD =

new file mode 100644
--- /dev/null
+++ b/tests/test-spawn-pipe-child.c
@@ -0,0 +1,113 @@
+/* Child program invoked by test-spawn-pipe..
+   Copyright (C) 2009-2011 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, 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.  */
+
+#include <config.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Get declarations of the Win32 API functions.  */
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+#endif
+
+/* Depending on arguments, this test intentionally closes stderr or
+   starts life with stderr closed.  So, we arrange to have fd 10
+   (outside the range of interesting fd's during the test) set up to
+   duplicate the original stderr.  */
+
+#define BACKUP_STDERR_FILENO 10
+#define ASSERT_STREAM myerr
+#include "macros.h"
+
+static FILE *myerr;
+
+/* In this file, we use only system functions, no overrides from gnulib.  */
+#undef atoi
+#undef close
+#undef fcntl
+#undef fdopen
+#undef read
+#undef write
+
+/* Return non-zero if FD is open.  */
+static int
+is_open (int fd)
+{
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+  /* On Win32, the initial state of unassigned standard file
+     descriptors is that they are open but point to an
+     INVALID_HANDLE_VALUE, and there is no fcntl.  */
+  return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE;
+#else
+# ifndef F_GETFL
+#  error Please port fcntl to your platform
+# endif
+  return 0 <= fcntl (fd, F_GETFL);
+#endif
+}
+
+int
+main (int argc, char *argv[])
+{
+  char buffer[2] = { 's', 't' };
+  int fd;
+
+  /* fd 2 might be closed, but fd BACKUP_STDERR_FILENO is the original
+     stderr.  */
+  myerr = fdopen (BACKUP_STDERR_FILENO, "w");
+  if (!myerr)
+    return 2;
+
+  ASSERT (argc == 2);
+
+  /* Read one byte from fd 0, and write its value plus one to fd 1.
+     fd 2 should be closed iff the argument is 1.  Check that no other file
+     descriptors leaked.  */
+
+  ASSERT (read (STDIN_FILENO, buffer, 2) == 1);
+
+  buffer[0]++;
+  ASSERT (write (STDOUT_FILENO, buffer, 1) == 1);
+
+  switch (atoi (argv[1]))
+    {
+    case 0:
+      /* Expect fd 2 is open.  */
+      ASSERT (is_open (STDERR_FILENO));
+      break;
+    case 1:
+      /* Expect fd 2 is closed.  */
+      ASSERT (! is_open (STDERR_FILENO));
+      break;
+    default:
+      ASSERT (0);
+    }
+
+  for (fd = 3; fd < 7; fd++)
+    {
+      errno = 0;
+      ASSERT (close (fd) == -1);
+      ASSERT (errno == EBADF);
+    }
+
+  return 0;
+}

--- a/tests/test-spawn-pipe.c
+++ b/tests/test-spawn-pipe.c
@@ -20,7 +20,6 @@
 #include "spawn-pipe.h"
 #include "wait-process.h"
 
-#include <errno.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -38,70 +37,23 @@
 
 static FILE *myerr;
 
-/* Code executed by the child process.  argv[1] = "child".  */
-static int
-child_main (int argc, char *argv[])
-{
-  char buffer[2] = { 's', 't' };
-  int fd;
-  int ret;
-
-  ASSERT (argc == 3);
-
-  /* Read one byte from fd 0, and write its value plus one to fd 1.
-     fd 2 should be closed iff the argument is 1.  Check that no other file
-     descriptors leaked.  */
-
-  ASSERT (read (STDIN_FILENO, buffer, 2) == 1);
-
-  buffer[0]++;
-  ASSERT (write (STDOUT_FILENO, buffer, 1) == 1);
-
-  errno = 0;
-  ret = dup2 (STDERR_FILENO, STDERR_FILENO);
-  switch (atoi (argv[2]))
-    {
-    case 0:
-      /* Expect fd 2 is open.  */
-      ASSERT (ret == STDERR_FILENO);
-      break;
-    case 1:
-      /* Expect fd 2 is closed.  */
-      ASSERT (ret == -1);
-      ASSERT (errno == EBADF);
-      break;
-    default:
-      ASSERT (false);
-    }
-
-  for (fd = 3; fd < 7; fd++)
-    {
-      errno = 0;
-      ASSERT (close (fd) == -1);
-      ASSERT (errno == EBADF);
-    }
-
-  return 0;
-}
-
 /* Create a bi-directional pipe to a test child, and validate that the
-   child program returns the expected output.  The child is the same
-   program as the parent ARGV0, but with different arguments.
+   child program returns the expected output.
+   PROG is the program to run in the child process.
    STDERR_CLOSED is true if we have already closed fd 2.  */
 static void
-test_pipe (const char *argv0, bool stderr_closed)
+test_pipe (const char *prog, bool stderr_closed)
 {
   int fd[2];
-  char *argv[4];
+  char *argv[3];
   pid_t pid;
   char buffer[2] = { 'a', 't' };
 
   /* Set up child.  */
-  argv[0] = (char *) argv0;
-  argv[1] = (char *) "child";
-  argv[2] = (char *) (stderr_closed ? "1" : "0");
-  argv[3] = NULL;
-  pid = create_pipe_bidi (argv0, argv0, argv, false, true, true, fd);
+  argv[0] = (char *) prog;
+  argv[1] = (char *) (stderr_closed ? "1" : "0");
+  argv[2] = NULL;
+  pid = create_pipe_bidi (prog, prog, argv, false, true, true, fd);
   ASSERT (0 <= pid);
   ASSERT (STDERR_FILENO < fd[0]);
   ASSERT (STDERR_FILENO < fd[1]);
@@ -114,7 +66,7 @@
   ASSERT (read (fd[0], buffer, 2) == 1);
 
   /* Wait for child.  */
-  ASSERT (wait_subprocess (pid, argv0, true, false, true, true, NULL) == 0);
+  ASSERT (wait_subprocess (pid, prog, true, false, true, true, NULL) == 0);
   ASSERT (close (fd[0]) == 0);
 
   /* Check the result.  */
@@ -122,18 +74,25 @@
   ASSERT (buffer[1] == 't');
 }
 
-/* Code executed by the parent process.  */
-static int
-parent_main (int argc, char *argv[])
+int
+main (int argc, char *argv[])
 {
   int test;
   int fd;
 
-  ASSERT (argc == 2);
+  if (argc != 3)
+    {
+      fprintf (stderr, "%s: need 2 arguments\n", argv[0]);
+      return 2;
+    }
+  /* We might close fd 2 later, so save it in fd 10.  */
+  if (dup2 (STDERR_FILENO, BACKUP_STDERR_FILENO) != BACKUP_STDERR_FILENO
+      || (myerr = fdopen (BACKUP_STDERR_FILENO, "w")) == NULL)
+    return 2;
 
   /* Selectively close various standard fds, to verify the child process is
      not impacted by this.  */
-  test = atoi (argv[1]);
+  test = atoi (argv[2]);
   switch (test)
     {
     case 0:
@@ -174,31 +133,7 @@
   for (fd = 3; fd < 7; fd++)
     close (fd);
 
-  test_pipe (argv[0], test >= 4);
+  test_pipe (argv[1], test >= 4);
 
   return 0;
 }
-
-int
-main (int argc, char *argv[])
-{
-  if (argc < 2)
-    {
-      fprintf (stderr, "%s: need arguments\n", argv[0]);
-      return 2;
-    }
-  if (strcmp (argv[1], "child") == 0)
-    {
-      /* fd 2 might be closed, but fd BACKUP_STDERR_FILENO is the original
-         stderr.  */
-      myerr = fdopen (BACKUP_STDERR_FILENO, "w");
-      if (!myerr)
-        return 2;
-      return child_main (argc, argv);
-    }
-  /* We might close fd 2 later, so save it in fd 10.  */
-  if (dup2 (STDERR_FILENO, BACKUP_STDERR_FILENO) != BACKUP_STDERR_FILENO
-      || (myerr = fdopen (BACKUP_STDERR_FILENO, "w")) == NULL)
-    return 2;
-  return parent_main (argc, argv);
-}

--- a/tests/test-spawn-pipe.sh
+++ b/tests/test-spawn-pipe.sh
@@ -2,7 +2,7 @@
 
 st=0
 for i in 0 1 2 3 4 5 6 7 ; do
-  ./test-spawn-pipe${EXEEXT} $i \
+  ./test-spawn-pipe${EXEEXT} ./test-spawn-pipe-child${EXEEXT} $i \
     || { echo test-spawn-pipe.sh: iteration $i failed >&2; st=1; }
 done
 exit $st