From ccf5ffdbe90331e355692bf8e59fab9b584427b4 Mon Sep 17 00:00:00 2001
From: kre <kre@NetBSD.org>
Date: Sat, 9 Feb 2019 09:31:33 +0000
Subject: [PATCH] In the unlikely event that restarting a job fails (the fg bg
 and various %x commands) generate the most useful error message (from errno
 value) rather than whichever happened last.

In posix mode, cause the "jobs" command to delete records of completed
jobs it reports on (as posix requires) as is done in interactive shells.
We don't (won't) do this in !posix mode, as the ability to throw in a
"jobs" command in a script to debug what is happening is too useful to
lose -- and any script that is relying on "jobs" instead of "wait" to
cleanup background processes (from the sh jobs table, sh always collects
zombies from the kernel) is absurd and not worth considering (besides
which I've never seen one).
---
 bin/sh/jobs.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/bin/sh/jobs.c b/bin/sh/jobs.c
index fb78031d487d..2c1171b5160e 100644
--- a/bin/sh/jobs.c
+++ b/bin/sh/jobs.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: jobs.c,v 1.104 2019/02/09 03:35:55 kre Exp $	*/
+/*	$NetBSD: jobs.c,v 1.105 2019/02/09 09:31:33 kre Exp $	*/
 
 /*-
  * Copyright (c) 1991, 1993
@@ -37,7 +37,7 @@
 #if 0
 static char sccsid[] = "@(#)jobs.c	8.5 (Berkeley) 5/4/95";
 #else
-__RCSID("$NetBSD: jobs.c,v 1.104 2019/02/09 03:35:55 kre Exp $");
+__RCSID("$NetBSD: jobs.c,v 1.105 2019/02/09 09:31:33 kre Exp $");
 #endif
 #endif /* not lint */
 
@@ -374,16 +374,19 @@ STATIC void
 restartjob(struct job *jp)
 {
 	struct procstat *ps;
-	int i;
+	int i, e;
 
 	if (jp->state == JOBDONE)
 		return;
 	INTOFF;
-	for (i = 0; i < jp->nprocs; i++)
+	for (e = i = 0; i < jp->nprocs; i++) {
 		if (killpg(jp->ps[i].pid, SIGCONT) != -1)
 			break;
+		if (e == 0 && errno != ESRCH)
+			e = errno;
+	}
 	if (i >= jp->nprocs)
-		error("Cannot continue job (%s)", strerror(errno));
+		error("Cannot continue job (%s)", strerror(e ? e : ESRCH));
 	for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) {
 		if (WIFSTOPPED(ps->status)) {
 			VTRACE(DBG_JOBS, (
@@ -535,13 +538,15 @@ jobscmd(int argc, char **argv)
 			mode = SHOW_PID;
 		else
 			mode = SHOW_PGID;
-	if (!iflag)
+
+	if (!iflag && !posix)
 		mode |= SHOW_NO_FREE;
-	if (*argptr)
+
+	if (*argptr) {
 		do
 			showjob(out1, getjob(*argptr,0), mode);
 		while (*++argptr);
-	else
+	} else
 		showjobs(out1, mode);
 	return 0;
 }