Include <grp.h> for the setgroups function.  This avoids an implicit

function declaration and build failures with C99 compilers that do not

support them.

Submitted upstream: <https://github.com/steve-o/openpgm/pull/73>

diff -ur openpgm-release-5-2-122.orig/openpgm/pgm/configure.ac openpgm-release-5-2-122/openpgm/pgm/configure.ac

--- openpgm-release-5-2-122.orig/openpgm/pgm/configure.ac	2012-12-04 03:56:54.000000000 +0100

+++ openpgm-release-5-2-122/openpgm/pgm/configure.ac	2023-01-03 16:07:39.751560631 +0100

@@ -62,7 +62,7 @@

 # Checks for header files.

 AC_FUNC_ALLOCA

-AC_CHECK_HEADERS([arpa/inet.h fcntl.h float.h inttypes.h libintl.h limits.h locale.h malloc.h memory.h netdb.h netinet/in.h stddef.h stdint.h stdlib.h string.h strings.h sys/ioctl.h sys/param.h sys/socket.h sys/time.h sys/timeb.h syslog.h unistd.h wchar.h])

+AC_CHECK_HEADERS([arpa/inet.h fcntl.h float.h grp.h inttypes.h libintl.h limits.h locale.h malloc.h memory.h netdb.h netinet/in.h stddef.h stdint.h stdlib.h string.h strings.h sys/ioctl.h sys/param.h sys/socket.h sys/time.h sys/timeb.h syslog.h unistd.h wchar.h])

 # Checks for typedefs, structures, and compiler characteristics.

 AC_HEADER_STDBOOL

diff -ur openpgm-release-5-2-122.orig/openpgm/pgm/engine.c openpgm-release-5-2-122/openpgm/pgm/engine.c

--- openpgm-release-5-2-122.orig/openpgm/pgm/engine.c	2023-01-03 16:03:16.834181524 +0100

+++ openpgm-release-5-2-122/openpgm/pgm/engine.c	2023-01-03 16:08:05.458304376 +0100

@@ -31,6 +31,10 @@

 #	include <config.h>

 #endif

+#ifdef HAVE_GRP_H

+#	include <grp.h>

+#endif

+

 #ifndef _BSD_SOURCE

 #	define _BSD_SOURCE	1	/* getprotobyname_r */

 #endif