From ba0ca3d3cf6543a0fade725d2389d6e3d941d186 Mon Sep 17 00:00:00 2001
From: guenther <>
Date: Fri, 15 Aug 2014 04:14:36 +0000
Subject: [PATCH] XPG requires insque() and remque() to work with linear lists
 and not just circular lists.  Amazingly, they managed to extend the
 requirements to no longer match the behavior of the VAX instructions they
 were modeled after, so the trivial VAX ASM versions have to go.  Nice job
 breaking it, X/Open!

Based on a diff from enh (at) google.com
ok miod@
---
 src/lib/libc/stdlib/Makefile.inc | 15 +++++----------
 src/lib/libc/stdlib/insque.c     | 20 +++++++++++++-------
 src/lib/libc/stdlib/remque.c     | 12 ++++++++----
 3 files changed, 26 insertions(+), 21 deletions(-)

diff --git a/src/lib/libc/stdlib/Makefile.inc b/src/lib/libc/stdlib/Makefile.inc
index 80c3e5f5..0c0b1499 100644
--- a/src/lib/libc/stdlib/Makefile.inc
+++ b/src/lib/libc/stdlib/Makefile.inc
@@ -1,13 +1,14 @@
-#	$OpenBSD: Makefile.inc,v 1.53 2014/05/08 21:43:49 deraadt Exp $
+#	$OpenBSD: Makefile.inc,v 1.54 2014/08/15 04:14:36 guenther Exp $
 
 # stdlib sources
 .PATH: ${LIBCSRCDIR}/arch/${MACHINE_CPU}/stdlib ${LIBCSRCDIR}/stdlib
 
 SRCS+=	a64l.c abort.c atexit.c atoi.c atof.c atol.c atoll.c bsearch.c \
 	cfree.c exit.c ecvt.c gcvt.c getenv.c getopt_long.c \
-	getsubopt.c hcreate.c heapsort.c imaxabs.c imaxdiv.c l64a.c llabs.c \
-	lldiv.c lsearch.c malloc.c reallocarray.c merge.c posix_pty.c \
-	qsort.c radixsort.c rand.c random.c realpath.c setenv.c strtoimax.c \
+	getsubopt.c hcreate.c heapsort.c imaxabs.c imaxdiv.c insque.c \
+	l64a.c llabs.c lldiv.c lsearch.c malloc.c reallocarray.c \
+	merge.c posix_pty.c qsort.c radixsort.c rand.c random.c \
+	realpath.c remque.c setenv.c strtoimax.c \
 	strtol.c strtoll.c strtonum.c strtoul.c strtoull.c strtoumax.c \
 	system.c tfind.c tsearch.c _rand48.c drand48.c erand48.c jrand48.c \
 	lcong48.c lrand48.c mrand48.c nrand48.c seed48.c srand48.c qabs.c \
@@ -24,12 +25,6 @@ SRCS+=	abs.c div.c labs.c ldiv.c
 SRCS+=	abs.c div.c labs.c ldiv.c
 .endif
 
-.if (${MACHINE_CPU} == "vax")
-SRCS+=	insque.S remque.S
-.else
-SRCS+=	insque.c remque.c
-.endif
-
 MAN+=	a64l.3 abort.3 abs.3 alloca.3 atexit.3 atof.3 atoi.3 atol.3 atoll.3 \
 	bsearch.3 div.3 ecvt.3 exit.3 getenv.3 getopt.3 getopt_long.3 \
 	getsubopt.3 hcreate.3 imaxabs.3 imaxdiv.3 insque.3 labs.3 ldiv.3 \
diff --git a/src/lib/libc/stdlib/insque.c b/src/lib/libc/stdlib/insque.c
index 8724efec..590ff837 100644
--- a/src/lib/libc/stdlib/insque.c
+++ b/src/lib/libc/stdlib/insque.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: insque.c,v 1.2 2005/08/08 08:05:36 espie Exp $	*/
+/*	$OpenBSD: insque.c,v 1.3 2014/08/15 04:14:36 guenther Exp $	*/
 
 /*
  *  Copyright (c) 1993 John Brezak
@@ -28,6 +28,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <stdlib.h>
 #include <search.h>
 
 struct qelem {
@@ -38,11 +39,16 @@ struct qelem {
 void
 insque(void *entry, void *pred)
 {
-	struct qelem *e = (struct qelem *) entry;
-	struct qelem *p = (struct qelem *) pred;
+	struct qelem *e = entry;
+	struct qelem *p = pred;
 
-	e->q_forw = p->q_forw;
-	e->q_back = p;
-	p->q_forw->q_back = e;
-	p->q_forw = e;
+	if (p == NULL)
+		e->q_forw = e->q_back = NULL;
+	else {
+		e->q_forw = p->q_forw;
+		e->q_back = p;
+		if (p->q_forw != NULL)
+			p->q_forw->q_back = e;
+		p->q_forw = e;
+	}
 }
diff --git a/src/lib/libc/stdlib/remque.c b/src/lib/libc/stdlib/remque.c
index ae249ae0..71b74b2d 100644
--- a/src/lib/libc/stdlib/remque.c
+++ b/src/lib/libc/stdlib/remque.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: remque.c,v 1.2 2005/08/08 08:05:37 espie Exp $	*/
+/*	$OpenBSD: remque.c,v 1.3 2014/08/15 04:14:36 guenther Exp $	*/
 
 /*
  *  Copyright (c) 1993 John Brezak
@@ -28,6 +28,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <stdlib.h>
 #include <search.h>
 
 struct qelem {
@@ -38,7 +39,10 @@ struct qelem {
 void
 remque(void *element)
 {
-	struct qelem *e = (struct qelem *) element;
-	e->q_forw->q_back = e->q_back;
-	e->q_back->q_forw = e->q_forw;
+	struct qelem *e = element;
+
+	if (e->q_forw != NULL)
+		e->q_forw->q_back = e->q_back;
+	if (e->q_back != NULL)
+		e->q_back->q_forw = e->q_forw;
 }