🚀 go-pugleaf

From: ed@fred.MTXINU (Ed Gould)

Description:
	Tip does not set the uid correctly in the child process
	when it forks.
Repeat-By:
	Invoke tip and use ~s for a shell escape.  The shell will complain
	because the real end effective uid's are not the same.
Fix:
	Whenever tip forks, the real and effective uid and gid in the
	child should be set to the real id's from the time tip
	was invoked.  Apply the following diff to effect the fix.

	*** /usr/src/usr.bin/tip/cmds.c	Tue Aug 26 18:10:31 1986
	--- cmds.c.new			Fri Sep 26 10:21:36 1986
	***************
	*** 187,192 ****
	--- 187,194 ----
		} else {
			register int f;
	  
	+ 		setregid(gid, gid);
	+ 		setreuid(uid, uid);
			dup2(pdes[0], 0);
			close(pdes[0]);
			for (f = 3; f < 20; f++)
	***************
	*** 448,453 ****
	--- 450,457 ----
		} else {
			register int i;
	  
	+ 		setregid(gid, gid);
	+ 		setreuid(uid, uid);
			dup2(FD, 1);
			for (i = 3; i < 20; i++)
				close(i);
	***************
	*** 501,506 ****
	--- 505,512 ----
		} else {
			register int i;
	  
	+ 		setregid(gid, gid);
	+ 		setreuid(uid, uid);
			dup2(FD, 3);
			dup2(3, 4);
			for (i = 5; i < 20; i++)
	***************
	*** 541,546 ****
	--- 547,554 ----
			signal(SIGQUIT, SIG_DFL);
			return;
		} else {
	+ 		setregid(gid, gid);
	+ 		setreuid(uid, uid);
			signal(SIGQUIT, SIG_DFL);
			signal(SIGINT, SIG_DFL);
			if ((cp = rindex(value(SHELL), '/')) == NULL)
	***************
	*** 794,799 ****
	--- 802,809 ----
		}
		sprintf(cmdbuf, "echo %s", name);
		if ((pid = vfork()) == 0) {
	+ 		setregid(gid, gid);
	+ 		setreuid(uid, uid);
			Shell = value(SHELL);
			if (Shell == NOSTR)
				Shell = "/bin/sh";