lseek: avoid bash 3.2 broken pipe bug

Avoid a spurious message caused by SIGPIPE handling, as well as
avoiding bash 3.2 messages even when SIGPIPE is not handled.

* m4/lseek.m4 (gl_FUNC_LSEEK): Drain pipe, to avoid spurious
warning from bash 3.2.
Reported by Ben Pfaff, with analysis from Bruno Haible.

Signed-off-by: Eric Blake <eblake@redhat.com>

diff --git a/ChangeLog b/ChangeLog
index ddb7216..892c85e 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2010-02-22  Eric Blake  <eblake@redhat.com>
 
+       lseek: avoid bash 3.2 broken pipe bug
+       * m4/lseek.m4 (gl_FUNC_LSEEK): Drain pipe, to avoid spurious
+       warning from bash 3.2.
+       Reported by Ben Pfaff, with analysis from Bruno Haible.
+
        bootstrap: support non-FSF copyright holder
        * build-aux/bootstrap (COPYRIGHT_HOLDER, with_gettext): Allow
        bootstrap.conf override of COPYRIGHT_HOLDER.

diff --git a/m4/lseek.m4 b/m4/lseek.m4
index f308495..9bf4dc2 100644 (file)
--- a/m4/lseek.m4
+++ b/m4/lseek.m4
@@ -1,4 +1,4 @@
-# lseek.m4 serial 4
+# lseek.m4 serial 5
 dnl Copyright (C) 2007, 2009, 2010 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -21,7 +21,8 @@ int main ()
 }],
          [if test -s conftest$ac_exeext \
              && ./conftest$ac_exeext < conftest.$ac_ext \
-             && { echo hi | ./conftest$ac_exeext; test $? = 1; }; then
+             && test 1 = "`echo hi \
+               | { ./conftest$ac_exeext; echo $?; cat >/dev/null; }`"; then
             gl_cv_func_lseek_pipe=yes
           else
             gl_cv_func_lseek_pipe=no