MFC r268926, r268930, r268983:

Use a correct errno in freopen.
Use EBADF instead of EINVAL when working around incorrect O_ACCMODE.

Adjust errno on failed prepwrite.

rewind: always clear error indicator as required by POSIX.

Obtained from:	Apple Inc. (Libc 997.90.3)
Phabric:	D442

1 files changed, 4 insertions, 1 deletions

diff --git a/lib/libc/stdio/wbuf.c b/lib/libc/stdio/wbuf.c
index 3f697e2..5bc3c4d 100644
--- a/lib/libc/stdio/wbuf.c
+++ b/lib/libc/stdio/wbuf.c
@@ -36,6 +36,7 @@ static char sccsid[] = "@(#)wbuf.c	8.1 (Berkeley) 6/4/93";
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#include <errno.h>
 #include <stdio.h>
 #include "local.h"
 
@@ -59,8 +60,10 @@ __swbuf(int c, FILE *fp)
 	 * calls might wrap _w from negative to positive.
 	 */
 	fp->_w = fp->_lbfsize;
-	if (prepwrite(fp) != 0)
+	if (prepwrite(fp) != 0) {
+		errno = EBADF;
 		return (EOF);
+	}
 	c = (unsigned char)c;
 
 	ORIENT(fp, -1);