From b0ae9b37424255b4943e224b9200ec99351b8667 Mon Sep 17 00:00:00 2001
From: "Thomas E. Spanjaard" <tgen@dragonflybsd.org>
Date: Wed, 6 Dec 2006 11:58:57 +0000
Subject: [PATCH] Fix a bug in our confstr(3) implementation, it did not
 conform to POSIX 1003.2. It returned -1 for errors where it should have
 returned 0.

Also, fix the only consumer of confstr(3) in our tree, getconf(1).

Dragonfly-bug:	<http://bugs.dragonflybsd.org/issue393>
Reviewed-by:	Victor Balada Diaz <victor@bsdes.net>
---
 lib/libc/gen/confstr.3    |  8 +++++---
 lib/libc/gen/confstr.c    | 11 +++++++----
 usr.bin/getconf/getconf.c |  5 +++--
 3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/lib/libc/gen/confstr.3 b/lib/libc/gen/confstr.3
index c6bea6b7e5..986a4cbd75 100644
--- a/lib/libc/gen/confstr.3
+++ b/lib/libc/gen/confstr.3
@@ -31,9 +31,9 @@
 .\"
 .\"	@(#)confstr.3	8.1 (Berkeley) 6/4/93
 .\" $FreeBSD: src/lib/libc/gen/confstr.3,v 1.5.2.5 2001/12/14 18:33:50 ru Exp $
-.\" $DragonFly: src/lib/libc/gen/confstr.3,v 1.3 2006/05/26 19:39:36 swildner Exp $
+.\" $DragonFly: src/lib/libc/gen/confstr.3,v 1.4 2006/12/06 11:58:57 tgen Exp $
 .\"
-.Dd June 4, 1993
+.Dd December 5, 2006
 .Dt CONFSTR 3
 .Os
 .Sh NAME
@@ -90,7 +90,7 @@ environment variable that finds all the standard utilities.
 .Sh RETURN VALUES
 If the call to
 .Fn confstr
-is not successful, \-1 is returned and
+is not successful, 0 is returned and
 .Va errno
 is set appropriately.
 Otherwise, if the variable does not have a configuration defined value,
@@ -123,6 +123,8 @@ argument is invalid.
 .El
 .Sh SEE ALSO
 .Xr sysctl 3
+.Rs
+.St -p1003.2
 .Sh HISTORY
 The
 .Fn confstr
diff --git a/lib/libc/gen/confstr.c b/lib/libc/gen/confstr.c
index 07f28b97c1..9206da9c2c 100644
--- a/lib/libc/gen/confstr.c
+++ b/lib/libc/gen/confstr.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  * @(#)confstr.c	8.1 (Berkeley) 6/4/93
- * $DragonFly: src/lib/libc/gen/confstr.c,v 1.3 2005/11/13 00:07:42 swildner Exp $
+ * $DragonFly: src/lib/libc/gen/confstr.c,v 1.4 2006/12/06 11:58:57 tgen Exp $
  */
 
 #include <sys/param.h>
@@ -55,15 +55,18 @@ confstr(int name, char *buf, size_t len)
 		mib[0] = CTL_USER;
 		mib[1] = USER_CS_PATH;
 		if (sysctl(mib, 2, NULL, &tlen, NULL, 0) == -1)
-			return (-1);
+			/*
+			 * POSIX 1003.2 requires errors to return 0.
+			 */
+			return (0);
 		if (len != 0 && buf != NULL) {
 			if ((p = malloc(tlen)) == NULL)
-				return (-1);
+				return (0);	/* POSIX 1003.2 */
 			if (sysctl(mib, 2, p, &tlen, NULL, 0) == -1) {
 				sverrno = errno;
 				free(p);
 				errno = sverrno;
-				return (-1);
+				return (0);	/* POSIX 1003.2 */
 			}
 			/*
 			 * POSIX 1003.2 requires partial return of
diff --git a/usr.bin/getconf/getconf.c b/usr.bin/getconf/getconf.c
index 4c3db534cc..b96012b84d 100644
--- a/usr.bin/getconf/getconf.c
+++ b/usr.bin/getconf/getconf.c
@@ -27,7 +27,7 @@
  * SUCH DAMAGE.
  *
  * $FreeBSD: src/usr.bin/getconf/getconf.c,v 1.6.2.1 2002/10/27 04:18:40 wollman Exp $
- * $DragonFly: src/usr.bin/getconf/getconf.c,v 1.3 2003/11/04 20:25:45 dillon Exp $
+ * $DragonFly: src/usr.bin/getconf/getconf.c,v 1.4 2006/12/06 11:58:57 tgen Exp $
  */
 
 #include <sys/types.h>
@@ -141,8 +141,9 @@ do_confstr(const char *name, int key)
 	char *buf;
 	size_t len;
 
+	errno = 0;
 	len = confstr(key, 0, 0);
-	if (len == (size_t)-1)
+	if (len == 0 && errno != 0)
 		err(EX_OSERR, "confstr: %s", name);
 	
 	if (len == 0) {
-- 
2.41.0