Set errno to EINVAL when fgets is given a non-positive size.

OK millert otto

2 files changed, 11 insertions, 4 deletions

diff --git a/lib/libc/stdio/fgets.3 b/lib/libc/stdio/fgets.3
index d459f35958f..13b213088ef 100644
--- a/lib/libc/stdio/fgets.3
+++ b/lib/libc/stdio/fgets.3
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: fgets.3,v 1.28 2007/09/07 05:17:59 cloder Exp $
+.\"	$OpenBSD: fgets.3,v 1.29 2009/06/02 22:28:18 ray Exp $
 .\"
 .\" Copyright (c) 1990, 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -31,7 +31,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: September 7 2007 $
+.Dd $Mdocdate: June 2 2009 $
 .Dt FGETS 3
 .Os
 .Sh NAME
@@ -114,6 +114,10 @@ is 1.
 The given
 .Fa stream
 is not a readable stream.
+.It Bq Er EINVAL
+The given
+.Fa size
+is less than or equal to 0.
 .El
 .Pp
 The function
diff --git a/lib/libc/stdio/fgets.c b/lib/libc/stdio/fgets.c
index 92fdcf78ff5..536935256be 100644
--- a/lib/libc/stdio/fgets.c
+++ b/lib/libc/stdio/fgets.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fgets.c,v 1.10 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: fgets.c,v 1.11 2009/06/02 22:28:18 ray Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -31,6 +31,7 @@
  * SUCH DAMAGE.
  */
 
+#include <errno.h>
 #include <stdio.h>
 #include <string.h>
 #include "local.h"
@@ -48,8 +49,10 @@ fgets(char *buf, int n, FILE *fp)
 	char *s;
 	unsigned char *p, *t;
 
-	if (n <= 0)		/* sanity check */
+	if (n <= 0) {		/* sanity check */
+		errno = EINVAL;
 		return (NULL);
+	}
 
 	_SET_ORIENTATION(fp, -1);
 	s = buf;