test for presence of stddef.h
separate arg requirements for getpgrp() and setpgrp()
diff --git a/acconfig.h b/acconfig.h
index a68c11c..eee1b84 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -12,10 +12,12 @@
 /* Define to `long' if <time.h> doesn't define.  */
 #undef clock_t
 
-/* Define if getpgrp() must be called as getpgrp(0)
-   and (consequently) setpgrp() as setpgrp(0, 0). */
+/* Define if getpgrp() must be called as getpgrp(0). */
 #undef GETPGRP_HAVE_ARG
 
+/* Define if setpgrp() must be called as setpgrp(0, 0). */
+#undef SETPGRP_HAVE_ARG
+
 /* Define this if your time.h defines altzone */
 #undef HAVE_ALTZONE
 
diff --git a/config.h.in b/config.h.in
index d91fbd9..779ea63 100644
--- a/config.h.in
+++ b/config.h.in
@@ -90,10 +90,12 @@
 /* Define to `long' if <time.h> doesn't define.  */
 #undef clock_t
 
-/* Define if getpgrp() must be called as getpgrp(0)
-   and (consequently) setpgrp() as setpgrp(0, 0). */
+/* Define if getpgrp() must be called as getpgrp(0). */
 #undef GETPGRP_HAVE_ARG
 
+/* Define if setpgrp() must be called as setpgrp(0, 0). */
+#undef SETPGRP_HAVE_ARG
+
 /* Define this if your time.h defines altzone */
 #undef HAVE_ALTZONE
 
@@ -237,6 +239,9 @@
 /* Define if you have the <stdarg.h> header file.  */
 #undef HAVE_STDARG_H
 
+/* Define if you have the <stddef.h> header file.  */
+#undef HAVE_STDDEF_H
+
 /* Define if you have the <stdlib.h> header file.  */
 #undef HAVE_STDLIB_H
 
diff --git a/configure.in b/configure.in
index 6ca1f5a..2d2adb3 100644
--- a/configure.in
+++ b/configure.in
@@ -46,7 +46,7 @@
 
 # checks for header files
 AC_STDC_HEADERS
-AC_HAVE_HEADERS(dlfcn.h fcntl.h limits.h signal.h stdarg.h stdlib.h thread.h unistd.h utime.h sys/audioio.h sys/param.h sys/select.h sys/time.h sys/times.h sys/un.h sys/utsname.h)
+AC_HAVE_HEADERS(dlfcn.h fcntl.h limits.h signal.h stdarg.h stddef.h stdlib.h thread.h unistd.h utime.h sys/audioio.h sys/param.h sys/select.h sys/time.h sys/times.h sys/un.h sys/utsname.h)
 AC_DIR_HEADER
 
 # checks for typedefs
@@ -196,6 +196,7 @@
 AC_HAVE_FUNCS(chown clock dlopen ftime gettimeofday getpeername getpgrp getpid getwd link lstat nice readlink select setgid setuid setsid setpgid setpgrp setvbuf siginterrupt symlink tcgetpgrp tcsetpgrp times uname waitpid)
 AC_REPLACE_FUNCS(dup2 getcwd strerror memmove)
 AC_FUNC_CHECK(getpgrp, AC_COMPILE_CHECK([argument to getpgrp], [#include <unistd.h>], [getpgrp(0);], AC_DEFINE(GETPGRP_HAVE_ARG)))
++ AC_FUNC_CHECK(setpgrp, AC_COMPILE_CHECK([arguments to setpgrp], [#include <unistd.h>], [setpgrp(0,0);], AC_DEFINE(SETPGRP_HAVE_ARG)))
 
 # checks for structures
 AC_TIME_WITH_SYS_TIME