The test for setpgrp having two arguments didn't actually test anything.

For reasons unknown this suddenly started to matter (since Martin's 1.396
checkin? But why?), at least on MacOSX. Added a real test similar to the
getpgrp argument test.

configure

 #! /bin/sh
-# From configure.in Revision: 1.396 .
+# From configure.in Revision: 1.397 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.53 for python 2.3.
 #
@@ -908,7 +908,7 @@ esac
 # Don't blindly perform a `cd "$ac_dir"/$ac_foo && pwd` since $ac_foo can be
 # absolute.
 ac_abs_builddir=`cd "$ac_dir" && cd $ac_builddir && pwd`
-ac_abs_top_builddir=`cd "$ac_dir" && cd ${ac_top_builddir}. && pwd`
+ac_abs_top_builddir=`cd "$ac_dir" && cd $ac_top_builddir && pwd`
 ac_abs_srcdir=`cd "$ac_dir" && cd $ac_srcdir && pwd`
 ac_abs_top_srcdir=`cd "$ac_dir" && cd $ac_top_srcdir && pwd`
 
@@ -13011,22 +13011,29 @@ rm -f conftest.$ac_objext conftest.$ac_ext
 fi
 done
 
-echo "$as_me:$LINENO: checking whether setpgrp takes no argument" >&5
-echo $ECHO_N "checking whether setpgrp takes no argument... $ECHO_C" >&6
-if test "${ac_cv_func_setpgrp_void+set}" = set; then
+
+for ac_func in setpgrp
+do
+as_ac_var=`echo "ac_cv_func_$ac_func" | $as_tr_sh`
+echo "$as_me:$LINENO: checking for $ac_func" >&5
+echo $ECHO_N "checking for $ac_func... $ECHO_C" >&6
+if eval "test \"\${$as_ac_var+set}\" = set"; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
-else
-  if test "$cross_compiling" = yes; then
-  { { echo "$as_me:$LINENO: error: cannot check setpgrp when cross compiling" >&5
-echo "$as_me: error: cannot check setpgrp when cross compiling" >&2;}
-   { (exit 1); exit 1; }; }
 else
   cat >conftest.$ac_ext <<_ACEOF
 #line $LINENO "configure"
 #include "confdefs.h"
-#if HAVE_UNISTD_H
-# include <unistd.h>
+/* System header to define __stub macros and hopefully few prototypes,
+    which can conflict with char $ac_func (); below.  */
+#include <assert.h>
+/* Override any gcc2 internal prototype to avoid an error.  */
+#ifdef __cplusplus
+extern "C"
 #endif
+/* We use char because int might match the return type of a gcc2
+   builtin and then its argument prototype would still apply.  */
+char $ac_func ();
+char (*f) ();
 
 #ifdef F77_DUMMY_MAIN
 #  ifdef __cplusplus
@@ -13037,45 +13044,89 @@ else
 int
 main ()
 {
-/* If this system has a BSD-style setpgrp which takes arguments,
-  setpgrp(1, 1) will fail with ESRCH and return -1, in that case
-  exit successfully. */
-  exit (setpgrp (1,1) == -1 ? 0 : 1);
+/* The GNU C library defines this for functions which it implements
+    to always fail with ENOSYS.  Some functions are actually named
+    something starting with __ and the normal name is an alias.  */
+#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+choke me
+#else
+f = $ac_func;
+#endif
+
   ;
   return 0;
 }
 _ACEOF
-rm -f conftest$ac_exeext
+rm -f conftest.$ac_objext conftest$ac_exeext
 if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
   (eval $ac_link) 2>&5
   ac_status=$?
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } && { ac_try='./conftest$ac_exeext'
+  (exit $ac_status); } &&
+         { ac_try='test -s conftest$ac_exeext'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); }; }; then
-  ac_cv_func_setpgrp_void=no
+  eval "$as_ac_var=yes"
 else
-  echo "$as_me: program exited with status $ac_status" >&5
-echo "$as_me: failed program was:" >&5
+  echo "$as_me: failed program was:" >&5
 cat conftest.$ac_ext >&5
-( exit $ac_status )
-ac_cv_func_setpgrp_void=yes
-fi
-rm -f core core.* *.core conftest$ac_exeext conftest.$ac_objext conftest.$ac_ext
+eval "$as_ac_var=no"
 fi
+rm -f conftest.$ac_objext conftest$ac_exeext conftest.$ac_ext
 fi
-echo "$as_me:$LINENO: result: $ac_cv_func_setpgrp_void" >&5
-echo "${ECHO_T}$ac_cv_func_setpgrp_void" >&6
-if test $ac_cv_func_setpgrp_void = yes; then
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_var'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_var'}'`" >&6
+if test `eval echo '${'$as_ac_var'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_func" | $as_tr_cpp` 1
+_ACEOF
+ cat >conftest.$ac_ext <<_ACEOF
+#line $LINENO "configure"
+#include "confdefs.h"
+#include <unistd.h>
+#ifdef F77_DUMMY_MAIN
+#  ifdef __cplusplus
+     extern "C"
+#  endif
+   int F77_DUMMY_MAIN() { return 1; }
+#endif
+int
+main ()
+{
+setpgrp(0,0);
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+         { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
 
 cat >>confdefs.h <<\_ACEOF
-#define SETPGRP_VOID 1
+#define SETPGRP_HAVE_ARG 1
 _ACEOF
 
+
+else
+  echo "$as_me: failed program was:" >&5
+cat conftest.$ac_ext >&5
+fi
+rm -f conftest.$ac_objext conftest.$ac_ext
+
 fi
+done
 
 
 for ac_func in gettimeofday
@@ -17671,7 +17722,7 @@ esac
 # Don't blindly perform a `cd "$ac_dir"/$ac_foo && pwd` since $ac_foo can be
 # absolute.
 ac_abs_builddir=`cd "$ac_dir" && cd $ac_builddir && pwd`
-ac_abs_top_builddir=`cd "$ac_dir" && cd ${ac_top_builddir}. && pwd`
+ac_abs_top_builddir=`cd "$ac_dir" && cd $ac_top_builddir && pwd`
 ac_abs_srcdir=`cd "$ac_dir" && cd $ac_srcdir && pwd`
 ac_abs_top_srcdir=`cd "$ac_dir" && cd $ac_top_srcdir && pwd`
 

configure.in

@@ -1925,8 +1925,12 @@ AC_CHECK_FUNCS(getpgrp,
    [Define if getpgrp() must be called as getpgrp(0).])
  )
 )
-AC_FUNC_SETPGRP(AC_DEFINE(SETPGRP_HAVE_ARG, 1,
-	   [Define if setpgrp() must be called as setpgrp(0, 0).])
+AC_CHECK_FUNCS(setpgrp,
+  AC_TRY_COMPILE([#include <unistd.h>],
+    [setpgrp(0,0);],
+    AC_DEFINE(SETPGRP_HAVE_ARG, 1,
+    [Define if setpgrp() must be called as setpgrp(0, 0).])
+  )
 )
 AC_CHECK_FUNCS(gettimeofday, 
   AC_TRY_COMPILE([#include <sys/time.h>],