zdtm: Test for pgids and sids

If I'm not mistaken this covers all the if-s in the
restore_pgid and restore_sid code.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/zdtm.sh

@@ -21,6 +21,7 @@ static/vdso00
 static/file_shared
 static/timers
 static/futex
+static/xids00
 streaming/pipe_loop00
 streaming/pipe_shared00
 transition/file_read

test/zdtm/live/static/Makefile

@@ -38,6 +38,7 @@ TST_NOFILE	=				\
 		selfexe00			\
 		sem				\
 		maps01				\
+		xids00				\
 #		jobctl00			\
 
 TST_FILE	=				\

test/zdtm/live/static/xids00.c

+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <signal.h>
+#include <sys/wait.h>
+
+#include "zdtmtst.h"
+
+const char *test_doc	= "Check that environment didn't change";
+const char *test_author	= "Pavel Emelianov <xemul@parallels.com>";
+
+int main(int argc, char **argv)
+{
+	int tmp_pipe[2];
+	int pids[2], syncfd[2], stat, fail = 0;
+
+	test_init(argc, argv);
+
+	pipe(tmp_pipe);
+	pids[0] = test_fork();
+	if (pids[0] == 0) {
+		close(tmp_pipe[0]);
+
+		setsid();
+
+		close(tmp_pipe[1]);
+		test_waitsig();
+
+		if (getpid() != getsid(0))
+			exit(1);
+
+		if (getpid() != getpgid(0))
+			exit(2);
+
+		test_msg("P1 OK\n");
+		exit(0);
+	}
+	close(tmp_pipe[1]);
+	syncfd[0] = tmp_pipe[0];
+
+	pipe(tmp_pipe);
+	pids[1] = test_fork();
+	if (pids[1] == 0) {
+		int tmp_pipe_sub[2], pid;
+
+		close(tmp_pipe[0]);
+
+		setsid();
+
+		pipe(tmp_pipe_sub);
+		pid = test_fork();
+		if (pid == 0) {
+			close(tmp_pipe[1]);
+			close(tmp_pipe_sub[0]);
+
+			setpgid(0, 0);
+
+			close(tmp_pipe_sub[1]);
+			test_waitsig();
+
+			if (getsid(0) != getppid())
+				exit(1);
+			if (getpgid(0) != getpid())
+				exit(1);
+
+			exit(0);
+		}
+		close(tmp_pipe_sub[1]);
+
+		read(tmp_pipe_sub[0], &stat, 1);
+		close(tmp_pipe_sub[0]);
+
+		close(tmp_pipe[1]);
+
+		test_waitsig();
+
+		if (getpid() != getsid(0))
+			exit(1);
+
+		if (getpid() != getpgid(0))
+			exit(2);
+
+		kill(pid, SIGTERM);
+		wait(&stat);
+		if (!WIFEXITED(stat) || WEXITSTATUS(stat))
+			exit(3);
+
+		exit(0);
+	}
+	close(tmp_pipe[1]);
+	syncfd[1] = tmp_pipe[0];
+
+	read(syncfd[0], &stat, 1);
+	close(syncfd[0]);
+	read(syncfd[1], &stat, 1);
+	close(syncfd[1]);
+
+	test_daemon();
+	test_waitsig();
+
+	kill(pids[0], SIGTERM);
+	wait(&stat);
+	if (!WIFEXITED(stat) || WEXITSTATUS(stat)) {
+		test_msg("P1 stat %d/%d\n", WIFEXITED(stat), WEXITSTATUS(stat));
+		fail = 1;
+	}
+	kill(pids[1], SIGTERM);
+	wait(&stat);
+	if (!WIFEXITED(stat) || WEXITSTATUS(stat)) {
+		test_msg("P1 stat %d/%d\n", WIFEXITED(stat), WEXITSTATUS(stat));
+		fail = 1;
+	}
+
+	if (fail)
+		fail("Something failed");
+	else
+		pass();
+
+	return 0;
+}