The SETPGRP_VOID check is reversed in autoconf 2.52

[Akinori MUSHA]

Hi,

Please take a look at the SETPGRP_VOID check in AC_FUNC_SETPGRP in
acfunctions.m4; it is totally reversed.  It used to be correct in
autoconf 2.13 and prior but got broken in 2.52.

Attached is a patch that fixes the bug.  If this system has a
BSD-style setpgrp which takes arguments, setpgrp(1, 1) will fail with
ESRCH and return -1, in that case the test program should exit
successfully with 0, as noted in the comment.

-- 
                     /
                    /__  __            Akinori.org / MUSHA.org
                   / )  )  ) )  /     FreeBSD.org / Ruby-lang.org
Akinori MUSHA aka / (_ /  ( (__(  @ iDaemons.org / and.or.jp

"Somewhere out of a memory.. of lighted streets on quiet nights.."

--- acfunctions.m4.orig Wed Jul 18 01:19:21 2001
+++ acfunctions.m4      Mon Feb 25 23:02:37 2002
@@ -1166,7 +1166,7 @@
 ],
 [/* If this system has a BSD-style setpgrp, which takes arguments, exit
    successfully.  */
-  exit (setpgrp (1,1) == -1);])],
+  exit (setpgrp (1,1) == -1 ? 0 : 1);])],
                [ac_cv_func_setpgrp_void=no],
                [ac_cv_func_setpgrp_void=yes],
                [AC_MSG_ERROR([cannot check setpgrp if cross compiling])])])