improve c-stack.m4

[Eric Blake]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

When looking at a report on a c-stack failure on Irix 5.3 [1], I noticed
that we weren't checking for success after calling sigaction.  Fixed as
follows:

[1] http://lists.gnu.org/archive/html/bug-m4/2008-09/msg00000.html

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (Cygwin)
Comment: Public key at home.comcast.net/~ericblake/eblake.gpg
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iEYEARECAAYFAki8oEwACgkQ84KuGfSFAYC9OgCgjlYITsiKigotkoqawqTPoIcR
xtQAoNUsP8m5cMyVgvoa5jh3HLUZdhQR
=7fUg
-----END PGP SIGNATURE-----

>From 6cac489854c1fb8b19a1e2d45ddb745fe32b0912 Mon Sep 17 00:00:00 2001
From: Eric Blake <address@hidden>
Date: Mon, 1 Sep 2008 19:59:38 -0600
Subject: [PATCH] c-stack: make configure-time check more robust

* m4/c-stack.m4 (AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC): Check for
successful sigaction call.
Reported by Tom G. Christensen.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog     |    7 +++++++
 m4/c-stack.m4 |    8 +++-----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index f741e0a..d6ca6d7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2008-09-01  Eric Blake  <address@hidden>
+
+       c-stack: make configure-time check more robust
+       * m4/c-stack.m4 (AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC): Check for
+       successful sigaction call.
+       Reported by Tom G. Christensen.
+
 2008-09-01  Simon Josefsson  <address@hidden>
 
        * lib/bitrotate.h (rotl8, rotr8): Add.
diff --git a/m4/c-stack.m4 b/m4/c-stack.m4
index 885b662..4f0300b 100644
--- a/m4/c-stack.m4
+++ b/m4/c-stack.m4
@@ -7,7 +7,7 @@
 
 # Written by Paul Eggert.
 
-# serial 5
+# serial 6
 
 AC_DEFUN([AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC],
   [# for STACK_DIRECTION
@@ -85,8 +85,7 @@ AC_DEFUN([AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC],
           setrlimit (RLIMIT_STACK, &rl);
           #endif
 
-          c_stack_action ();
-          return recurse ("\1");
+          return c_stack_action () || recurse ("\1");
         }
        ],
        [ac_cv_sys_stack_overflow_works=yes],
@@ -201,8 +200,7 @@ AC_DEFUN([AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC],
           setrlimit (RLIMIT_STACK, &rl);
           #endif
 
-          c_stack_action ();
-          return recurse ("\1");
+          return c_stack_action () || recurse ("\1");
         }
        ],
        [ac_cv_sys_xsi_stack_overflow_heuristic=yes],
-- 
1.6.0