Re: workaround ftello/fseeko on cygwin 1.5.x

[Eric Blake]

Eric Blake <ebb9 <at> byu.net> writes:

> > Put this into a separate compilation unit, so that fseeko and ftello can
> > share the same cache.
> 
> However, the idea of cygfreopen64 has merits on its own, since I plan on
> adding documentation in doc/functions/stdin.texi (and whatever happened to
> stdout and stderr.texi?), so maybe making cygfreopen64 a separate module
> would have other uses.

I'm not doing this part now.  I'm not sure I like the name cygfreopen64; the 
cyg- prefix is too narrow (perhaps there are other platforms where we can 
gracefully convert an existing fd/FILE from narrow to large), and -freopen64 
clashes with platforms that have freopen64 as part of their large file support 
and taking three parameters.  Maybe something like:

/* Ensure that FP supports the full range of off_t offsets.  Returns FP
   on success, and NULL if FP can only process long offsets and could not
   be converted.  This is most useful on stdin, stdout, and stderr.  */
FILE *
flarge (FILE *fp)
{
  if (sizeof (off_t) > sizeof (long int))
    {
#if defined __SL64 && defined __SCLE /* cygwin */
/* check for __SL64, and convert if necessary */
...
#elif
/* other platforms... */
#endif
    }
  return fp;
}

Here's what I'm committing:

2007-05-23  Eric Blake  <address@hidden>

        Fix fseeko/ftello on cygwin 1.5.24.
        * doc/functions/fseeko.texi (fseeko): Document the fix.
        * doc/functions/ftello.texi (ftello): Document the fix.
        * doc/functions/stdin.texi (stdin): Document the shortcoming.
        * doc/functions/stdout.text (stdout): New file.
        * doc/functions/stderr.text (stderr): New file.
        * doc/gnulib.texi (Function Substitutes): Use new files.
        * tests/test-fseeko.c (main): Check for broken fseeko on cygwin
        prior to 1.7.0.
        * tests/test-ftello.c (main): Likewise for ftello.
        * tests/test-fseeko.sh: New file.
        * tests/test-ftello.sh: New file.
        * modules/fseeko-tests (Makefile.am): Ensure test-fseeko is run
        with seekable stdin.
        * modules/ftello-tests (Makefile.am): Likewise for test-ftello.
        * m4/fseeko.m4 (gl_FUNC_FSEEKO): Detect the cygwin bug.
        (gl_REPLACE_FSEEKO): New macro.
        * m4/ftello.m4 (gl_FUNC_FTELLO, gl_REPLACE_FTELLO): Likewise.
        * modules/fseeko (Files): Distribute fseeko.c.
        * modules/ftello (Files): Distribute ftello.c.
        * lib/fseeko.c (rpl_fseeko) [__CYGWIN__]: Convert stdin to 64-bit
        mode.
        * lib/ftello.c (rpl_ftello): New file.
        * m4/stdio_h.m4 (gl_STDIO_H_DEFAULTS): Allow replacement of
        fseeko, ftello.
        (gl_STDIN_LARGE_OFFSET): New macro.
        * modules/stdio (Makefile.am): Perform the replacement.
        * lib/stdio_.h (rpl_fseeko, rpl_ftello): Define when needed.

Index: lib/fseeko.c
===================================================================
RCS file: /sources/gnulib/gnulib/lib/fseeko.c,v
retrieving revision 1.3
diff -u -p -r1.3 fseeko.c
--- lib/fseeko.c        29 Apr 2007 12:16:55 -0000      1.3
+++ lib/fseeko.c        24 May 2007 03:05:44 -0000
@@ -44,6 +44,19 @@ rpl_fseeko (FILE *fp, off_t offset, int 
 # else                                         /* FreeBSD, MacOS X, Cygwin */
 #  define fp_ub fp->_ub
 # endif
+# if defined __SL64 && defined __SCLE /* Cygwin */
+  if ((fp->_flags & __SL64) == 0)
+    {
+      /* Cygwin 1.5.0 through 1.5.24 failed to open stdin in 64-bit
+        mode; but has an fseeko that requires 64-bit mode.  */
+      FILE *tmp = fopen ("/dev/null", "r");
+      if (!tmp)
+       return -1;
+      fp->_flags |= __SL64;
+      fp->_seek64 = tmp->_seek64;
+      fclose (tmp);
+    }
+# endif
   if (fp->_p == fp->_bf._base
       && fp->_r == 0
       && fp->_w == ((fp->_flags & (__SLBF | __SNBF | __SRD)) == 0 /* fully 
buffered and not currently reading? */
Index: lib/ftello.c
===================================================================
RCS file: lib/ftello.c
diff -N lib/ftello.c
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ lib/ftello.c        24 May 2007 03:05:44 -0000
@@ -0,0 +1,45 @@
+/* An ftello() function that works around platform bugs.
+   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.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <stdio.h>
+
+#undef ftello
+#if !HAVE_FTELLO
+# define ftello ftell
+#endif
+
+off_t
+rpl_ftello (FILE *fp)
+{
+#if defined __SL64 && defined __SCLE /* Cygwin */
+  if ((fp->_flags & __SL64) == 0)
+    {
+      /* Cygwin 1.5.0 through 1.5.24 failed to open stdin in 64-bit
+        mode; but has an ftello that requires 64-bit mode.  */
+      FILE *tmp = fopen ("/dev/null", "r");
+      if (!tmp)
+       return -1;
+      fp->_flags |= __SL64;
+      fp->_seek64 = tmp->_seek64;
+      fclose (tmp);
+    }
+#endif
+  return ftello (fp);
+}
Index: lib/stdio_.h
===================================================================
RCS file: /sources/gnulib/gnulib/lib/stdio_.h,v
retrieving revision 1.25
diff -u -p -r1.25 stdio_.h
--- lib/stdio_.h        23 May 2007 22:00:35 -0000      1.25
+++ lib/stdio_.h        24 May 2007 03:05:44 -0000
@@ -42,7 +42,9 @@
 #include <stdarg.h>
 #include <stddef.h>
 
-#if (@GNULIB_FFLUSH@ && @REPLACE_FFLUSH@) || (@GNULIB_FSEEKO@ && !
@HAVE_FSEEKO@) || (@GNULIB_FTELLO@ && address@hidden@)
+#if (@GNULIB_FFLUSH@ && @REPLACE_FFLUSH@)                               \
+  || (@GNULIB_FSEEKO@ && (address@hidden@ || @REPLACE_FSEEKO@))          \
+  || (@GNULIB_FTELLO@ && (address@hidden@ || @REPLACE_FTELLO@))
 /* Get off_t.  */
 # include <sys/types.h>
 #endif
@@ -216,7 +218,7 @@ extern int vsprintf (char *str, const ch
 # endif
 #endif
 
-#if @GNULIB_FFLUSH@ && @REPLACE_FFLUSH@
+#if (@GNULIB_FFLUSH@ && @REPLACE_FFLUSH@) || (@GNULIB_FSEEKO@ && 
@REPLACE_FSEEKO@)
 /* Provide fseek, fseeko functions that are aware of a preceding fflush().  */
 # define fseeko rpl_fseeko
 extern int fseeko (FILE *fp, off_t offset, int whence);
@@ -250,6 +252,9 @@ typedef int verify_fseeko_types[2 * (siz
 /* Assume 'off_t' is the same type as 'long'.  */
 typedef int verify_ftello_types[2 * (sizeof (off_t) == sizeof (long)) - 1];
 #  define ftello ftell
+# elif @REPLACE_FTELLO@
+#  define ftello rpl_ftello
+extern off_t ftello (FILE *fp);
 # endif
 #elif defined GNULIB_POSIXCHECK
 # undef ftello
Index: doc/gnulib.texi
===================================================================
RCS file: /sources/gnulib/gnulib/doc/gnulib.texi,v
retrieving revision 1.40
diff -u -p -r1.40 gnulib.texi
--- doc/gnulib.texi     1 May 2007 22:37:10 -0000       1.40
+++ doc/gnulib.texi     24 May 2007 03:05:45 -0000
@@ -1543,7 +1543,9 @@ by Gnulib.
 * sscanf::
 * stat::
 * statvfs::
+* stderr::
 * stdin::
+* stdout::
 * strcasecmp::
 * strcat::
 * strchr::
@@ -2659,7 +2661,9 @@ by Gnulib.
 @include functions/sscanf.texi
 @include functions/stat.texi
 @include functions/statvfs.texi
address@hidden functions/stderr.texi
 @include functions/stdin.texi
address@hidden functions/stdout.texi
 @include functions/strcasecmp.texi
 @include functions/strcat.texi
 @include functions/strchr.texi
@@ -2877,3 +2881,8 @@ generated automatically.
 @printindex cp
 
 @bye
+
address@hidden Local Variables:
address@hidden indent-tabs-mode: nil
address@hidden whitespace-check-buffer-indent: nil
address@hidden End:
Index: doc/functions/fseeko.texi
===================================================================
RCS file: /sources/gnulib/gnulib/doc/functions/fseeko.texi,v
retrieving revision 1.1
diff -u -p -r1.1 fseeko.texi
--- doc/functions/fseeko.texi   1 May 2007 15:11:38 -0000       1.1
+++ doc/functions/fseeko.texi   24 May 2007 03:05:45 -0000
@@ -14,6 +14,8 @@ OSF/1 4.0, Solaris 2.5.1, mingw.
 @item
 The declaration of @code{fseeko} in @code{<stdio.h>} is not enabled by default
 on some platforms: glibc 2.3.6.
address@hidden
+This function fails on seekable stdin, stdout, and stderr: cygwin 1.5.x.
 @end itemize
 
 Portability problems not fixed by Gnulib:
Index: doc/functions/ftello.texi
===================================================================
RCS file: /sources/gnulib/gnulib/doc/functions/ftello.texi,v
retrieving revision 1.1
diff -u -p -r1.1 ftello.texi
--- doc/functions/ftello.texi   1 May 2007 15:11:38 -0000       1.1
+++ doc/functions/ftello.texi   24 May 2007 03:05:45 -0000
@@ -14,6 +14,8 @@ OSF/1 4.0, Solaris 2.5.1, mingw.
 @item
 The declaration of @code{ftello} in @code{<stdio.h>} is not enabled by default
 on some platforms: glibc 2.3.6.
address@hidden
+This function fails on seekable stdin, stdout, and stderr: cygwin 1.5.x.
 @end itemize
 
 Portability problems not fixed by Gnulib:
Index: doc/functions/stderr.texi
===================================================================
RCS file: doc/functions/stderr.texi
diff -N doc/functions/stderr.texi
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ doc/functions/stderr.texi   24 May 2007 03:05:45 -0000
@@ -0,0 +1,20 @@
address@hidden stderr
address@hidden @code{stderr}
address@hidden stderr
+
+POSIX specification: @url{http://www.opengroup.org/susv3xsh/stderr.html}
+
+Gnulib module: ---
+
+Portability problems fixed by Gnulib:
address@hidden
address@hidden itemize
+
+Portability problems not fixed by Gnulib:
address@hidden
address@hidden
+stderr is created in 32-bit mode instead of 64-bit mode: Cygwin 1.5.x.
+One workaround is to use freopen(NULL, ``w+'', stderr) on Cygwin 1.5.21
+or newer.  Another is to use the gnulib ftello module and do
+ftello(stderr).
address@hidden itemize
Index: doc/functions/stdin.texi
===================================================================
RCS file: /sources/gnulib/gnulib/doc/functions/stdin.texi,v
retrieving revision 1.1
diff -u -p -r1.1 stdin.texi
--- doc/functions/stdin.texi    1 May 2007 15:11:39 -0000       1.1
+++ doc/functions/stdin.texi    24 May 2007 03:05:45 -0000
@@ -12,4 +12,9 @@ Portability problems fixed by Gnulib:
 
 Portability problems not fixed by Gnulib:
 @itemize
address@hidden
+stdin is created in 32-bit mode instead of 64-bit mode: Cygwin 1.5.x.
+One workaround is to use freopen(NULL, ``r'', stdin) on Cygwin 1.5.21
+or newer.  Another is to use the gnulib ftello module and do
+ftello(stdin).
 @end itemize
Index: doc/functions/stdout.texi
===================================================================
RCS file: doc/functions/stdout.texi
diff -N doc/functions/stdout.texi
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ doc/functions/stdout.texi   24 May 2007 03:05:45 -0000
@@ -0,0 +1,20 @@
address@hidden stdout
address@hidden @code{stdout}
address@hidden stdout
+
+POSIX specification: @url{http://www.opengroup.org/susv3xsh/stdout.html}
+
+Gnulib module: ---
+
+Portability problems fixed by Gnulib:
address@hidden
address@hidden itemize
+
+Portability problems not fixed by Gnulib:
address@hidden
address@hidden
+stdout is created in 32-bit mode instead of 64-bit mode: Cygwin 1.5.x.
+One workaround is to use freopen(NULL, ``w'', stdout) on Cygwin 1.5.21
+or newer.  Another is to use the gnulib ftello module and do
+ftello(stdout).
address@hidden itemize
Index: m4/fseeko.m4
===================================================================
RCS file: /sources/gnulib/gnulib/m4/fseeko.m4,v
retrieving revision 1.3
diff -u -p -r1.3 fseeko.m4
--- m4/fseeko.m4        26 Apr 2007 09:33:12 -0000      1.3
+++ m4/fseeko.m4        24 May 2007 03:05:45 -0000
@@ -1,4 +1,4 @@
-# fseeko.m4 serial 1
+# fseeko.m4 serial 2
 dnl Copyright (C) 2007 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -8,12 +8,22 @@ AC_DEFUN([gl_FUNC_FSEEKO],
 [
   AC_REQUIRE([gl_STDIO_H_DEFAULTS])
   AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([gl_STDIN_LARGE_OFFSET])
   AC_CACHE_CHECK([for fseeko], [gl_cv_func_fseeko],
     [
       AC_TRY_LINK([#include <stdio.h>], [fseeko (stdin, 0, 0);],
-        [gl_cv_func_fseeko=yes], [gl_cv_func_fseeko=no])
+       [gl_cv_func_fseeko=yes], [gl_cv_func_fseeko=no])
     ])
   if test $gl_cv_func_fseeko = no; then
     HAVE_FSEEKO=0
+  elif test $gl_cv_var_stdin_large_offset = no; then
+    gl_REPLACE_FSEEKO
   fi
 ])
+
+AC_DEFUN([gl_REPLACE_FSEEKO],
+[
+  AC_LIBOBJ([fseeko])
+  AC_REQUIRE([gl_STDIO_H_DEFAULTS])
+  REPLACE_FSEEKO=1
+])
Index: m4/ftello.m4
===================================================================
RCS file: /sources/gnulib/gnulib/m4/ftello.m4,v
retrieving revision 1.1
diff -u -p -r1.1 ftello.m4
--- m4/ftello.m4        25 Apr 2007 07:51:53 -0000      1.1
+++ m4/ftello.m4        24 May 2007 03:05:45 -0000
@@ -1,4 +1,4 @@
-# ftello.m4 serial 1
+# ftello.m4 serial 2
 dnl Copyright (C) 2007 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -8,12 +8,22 @@ AC_DEFUN([gl_FUNC_FTELLO],
 [
   AC_REQUIRE([gl_STDIO_H_DEFAULTS])
   AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([gl_STDIN_LARGE_OFFSET])
   AC_CACHE_CHECK([for ftello], [gl_cv_func_ftello],
     [
       AC_TRY_LINK([#include <stdio.h>], [ftello (stdin);],
-        [gl_cv_func_ftello=yes], [gl_cv_func_ftello=no])
+       [gl_cv_func_ftello=yes], [gl_cv_func_ftello=no])
     ])
   if test $gl_cv_func_ftello = no; then
     HAVE_FTELLO=0
+  elif test $gl_cv_var_stdin_large_offset = no; then
+    gl_REPLACE_FTELLO
   fi
 ])
+
+AC_DEFUN([gl_REPLACE_FTELLO],
+[
+  AC_LIBOBJ([ftello])
+  AC_REQUIRE([gl_STDIO_H_DEFAULTS])
+  REPLACE_FTELLO=1
+])
Index: m4/stdio_h.m4
===================================================================
RCS file: /sources/gnulib/gnulib/m4/stdio_h.m4,v
retrieving revision 1.13
diff -u -p -r1.13 stdio_h.m4
--- m4/stdio_h.m4       25 Apr 2007 07:51:53 -0000      1.13
+++ m4/stdio_h.m4       24 May 2007 03:05:45 -0000
@@ -1,4 +1,4 @@
-# stdio_h.m4 serial 4
+# stdio_h.m4 serial 5
 dnl Copyright (C) 2007 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -47,6 +47,29 @@ AC_DEFUN([gl_STDIO_H_DEFAULTS],
   HAVE_VASPRINTF=1;        AC_SUBST([HAVE_VASPRINTF])
   REPLACE_VASPRINTF=0;     AC_SUBST([REPLACE_VASPRINTF])
   HAVE_FSEEKO=1;           AC_SUBST([HAVE_FSEEKO])
+  REPLACE_FSEEKO=0;        AC_SUBST([REPLACE_FSEEKO])
   HAVE_FTELLO=1;           AC_SUBST([HAVE_FTELLO])
+  REPLACE_FTELLO=0;        AC_SUBST([REPLACE_FTELLO])
   REPLACE_FFLUSH=0;        AC_SUBST([REPLACE_FFLUSH])
 ])
+
+dnl Code shared by fseeko and ftello.  Determine if large files are supported,
+dnl but stdin does not start as a large file by default.
+AC_DEFUN([gl_STDIN_LARGE_OFFSET],
+  [
+    AC_CACHE_CHECK([whether stdin defaults to large file offsets],
+      [gl_cv_var_stdin_large_offset],
+      [AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <stdio.h>],
+[#if defined __SL64 && defined __SCLE /* cygwin */
+  /* Cygwin 1.5.24 and earlier fail to put stdin in 64-bit mode, making
+     fseeko/ftello needlessly fail.  This bug was fixed at the same time
+     that cygwin started exporting asnprintf (cygwin 1.7.0), so we use
+     that as a link-time test for cross-compiles rather than building
+     a runtime test.  */
+  size_t s;
+  if (asnprintf (NULL, &s, ""))
+    return 0;
+#endif])],
+       [gl_cv_var_stdin_large_offset=yes],
+       [gl_cv_var_stdin_large_offset=no])])
+])
Index: modules/fseeko
===================================================================
RCS file: /sources/gnulib/gnulib/modules/fseeko,v
retrieving revision 1.2
diff -u -p -r1.2 fseeko
--- modules/fseeko      26 Apr 2007 09:33:12 -0000      1.2
+++ modules/fseeko      24 May 2007 03:05:45 -0000
@@ -2,6 +2,7 @@ Description:
 fseeko() function: Reposition a FILE stream.
 
 Files:
+lib/fseeko.c
 m4/fseeko.m4
 
 Depends-on:
Index: modules/fseeko-tests
===================================================================
RCS file: /sources/gnulib/gnulib/modules/fseeko-tests,v
retrieving revision 1.1
diff -u -p -r1.1 fseeko-tests
--- modules/fseeko-tests        25 Apr 2007 07:40:58 -0000      1.1
+++ modules/fseeko-tests        24 May 2007 03:05:45 -0000
@@ -1,10 +1,13 @@
 Files:
 tests/test-fseeko.c
+tests/test-fseeko.sh
 
 Depends-on:
 
 configure.ac:
 
 Makefile.am:
-TESTS += test-fseeko
+TESTS += test-fseeko.sh
+TESTS_ENVIRONMENT += EXEEXT='@EXEEXT@' srcdir='$(srcdir)'
 check_PROGRAMS += test-fseeko
+EXTRA_DIST += test-fseeko.sh
Index: modules/ftello
===================================================================
RCS file: /sources/gnulib/gnulib/modules/ftello,v
retrieving revision 1.2
diff -u -p -r1.2 ftello
--- modules/ftello      26 Apr 2007 09:33:12 -0000      1.2
+++ modules/ftello      24 May 2007 03:05:45 -0000
@@ -2,6 +2,7 @@ Description:
 ftello() function: Retrieve the position of a FILE stream.
 
 Files:
+lib/ftello.c
 m4/ftello.m4
 
 Depends-on:
Index: modules/ftello-tests
===================================================================
RCS file: /sources/gnulib/gnulib/modules/ftello-tests,v
retrieving revision 1.1
diff -u -p -r1.1 ftello-tests
--- modules/ftello-tests        25 Apr 2007 07:52:28 -0000      1.1
+++ modules/ftello-tests        24 May 2007 03:05:45 -0000
@@ -1,10 +1,13 @@
 Files:
 tests/test-ftello.c
+tests/test-ftello.sh
 
 Depends-on:
 
 configure.ac:
 
 Makefile.am:
-TESTS += test-ftello
+TESTS += test-ftello.sh
+TESTS_ENVIRONMENT += EXEEXT='@EXEEXT@' srcdir='$(srcdir)'
 check_PROGRAMS += test-ftello
+EXTRA_DIST += test-ftello.sh
Index: modules/stdio
===================================================================
RCS file: /sources/gnulib/gnulib/modules/stdio,v
retrieving revision 1.14
diff -u -p -r1.14 stdio
--- modules/stdio       17 May 2007 06:14:30 -0000      1.14
+++ modules/stdio       24 May 2007 03:05:45 -0000
@@ -47,7 +47,9 @@ stdio.h: stdio_.h
              -e 's|@''HAVE_VASPRINTF''@|$(HAVE_VASPRINTF)|g' \
              -e 's|@''REPLACE_VASPRINTF''@|$(REPLACE_VASPRINTF)|g' \
              -e 's|@''HAVE_FSEEKO''@|$(HAVE_FSEEKO)|g' \
+             -e 's|@''REPLACE_FSEEKO''@|$(REPLACE_FSEEKO)|g' \
              -e 's|@''HAVE_FTELLO''@|$(HAVE_FTELLO)|g' \
+             -e 's|@''REPLACE_FTELLO''@|$(REPLACE_FTELLO)|g' \
              -e 's|@''REPLACE_FFLUSH''@|$(REPLACE_FFLUSH)|g' \
              -e '/definition of GL_LINK_WARNING/r $(LINK_WARNING_H)' \
              < $(srcdir)/stdio_.h; \
Index: tests/test-fseeko.c
===================================================================
RCS file: /sources/gnulib/gnulib/tests/test-fseeko.c,v
retrieving revision 1.1
diff -u -p -r1.1 test-fseeko.c
--- tests/test-fseeko.c 25 Apr 2007 07:40:58 -0000      1.1
+++ tests/test-fseeko.c 24 May 2007 03:05:45 -0000
@@ -27,8 +27,6 @@
 int
 main ()
 {
-  off_t pos = fseeko (stdin, (off_t)0, SEEK_CUR);
-  (void)pos;
-
-  return 0;
+  /* This test assumes stdin is seekable.  */
+  return fseeko (stdin, (off_t)0, SEEK_CUR) != 0;
 }
Index: tests/test-fseeko.sh
===================================================================
RCS file: tests/test-fseeko.sh
diff -N tests/test-fseeko.sh
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ tests/test-fseeko.sh        24 May 2007 03:05:45 -0000
@@ -0,0 +1,3 @@
+#!/bin/sh
+
+./test-fseeko${EXEEXT} < "$srcdir/test-fseeko.sh"
Index: tests/test-ftello.c
===================================================================
RCS file: /sources/gnulib/gnulib/tests/test-ftello.c,v
retrieving revision 1.1
diff -u -p -r1.1 test-ftello.c
--- tests/test-ftello.c 25 Apr 2007 07:52:28 -0000      1.1
+++ tests/test-ftello.c 24 May 2007 03:05:45 -0000
@@ -27,8 +27,7 @@
 int
 main ()
 {
+  /* This test assumes stdin is seekable.  */
   off_t pos = ftello (stdin);
-  (void)pos;
-
-  return 0;
+  return pos < 0;
 }
Index: tests/test-ftello.sh
===================================================================
RCS file: tests/test-ftello.sh
diff -N tests/test-ftello.sh
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ tests/test-ftello.sh        24 May 2007 03:05:45 -0000
@@ -0,0 +1,3 @@
+#!/bin/sh
+
+./test-ftello${EXEEXT} < "$srcdir/test-ftello.sh"