qa: add setsid test to newlib

qa/lib/newlib/050-setsid.c

@@ -0,0 +1,53 @@
+#include <unistd.h>
+#include <sys/types.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+
+int
+main(int argc, char **argv)
+{
+	pid_t pid;
+	int p[2], ppgrp, opgrp, npgrp;
+	char c = '?';
+
+	if (pipe(p) != 0)
+		perror("pipe() error");
+	else {
+		ppgrp = getpgrp();
+		printf("parent's pid %d; process group id %d\n", getpid(), ppgrp);
+		if ((pid = fork()) == 0) {
+			opgrp = getpgrp();
+			printf("child's pid %d; process group id %d\n", getpid(), opgrp);
+			write(p[1], &c, 1);
+			setsid();
+			npgrp = getpgrp();
+			if(opgrp == npgrp){
+				printf("FAIL: setsid did not changed child's process group id\n");
+				exit(EXIT_FAILURE);
+			}
+			printf("child's process group id is now %d\n", npgrp);
+			sleep(5);
+			exit(EXIT_SUCCESS);
+		} else {
+			read(p[0], &c, 1);
+			sleep(3);
+			if(ppgrp != getpgrp()){
+				printf("FAIL: parent's process group id changed from %d to %d\n", ppgrp, getpgrp());
+				exit(EXIT_FAILURE);
+			}
+
+#ifndef WITH_SIGCHLD
+			npgrp = getsid(pid);
+			if(npgrp < 0){
+				printf("FAIL: parent's getsid(%d) failed with errno %d\n", pid, errno);
+				exit(EXIT_FAILURE);
+			}
+			if(npgrp == ppgrp){
+				printf("FAIL: parent's getsid(%d) returned old process group id that should be changed\n", pid);
+				exit(EXIT_FAILURE);
+			}
+#endif
+		}
+	}
+}