Adjust errno on failed prepwrite.

Obtained from:	Apple Inc. (Libc 997.90.3)
Phabric:	D442
MFC after:	1 week

3 files changed, 10 insertions, 3 deletions

diff --git a/lib/libc/stdio/vfprintf.c b/lib/libc/stdio/vfprintf.c
index ea47d36..e54e8ac 100644
--- a/lib/libc/stdio/vfprintf.c
+++ b/lib/libc/stdio/vfprintf.c
@@ -455,8 +455,10 @@ __vfprintf(FILE *fp, locale_t locale, const char *fmt0, va_list ap)
 		return (__xvprintf(fp, fmt0, ap));
 
 	/* sorry, fprintf(read_only_file, "") returns EOF, not 0 */
-	if (prepwrite(fp) != 0)
+	if (prepwrite(fp) != 0) {
+		errno = EBADF;
 		return (EOF);
+	}
 
 	convbuf = NULL;
 	fmt = (char *)fmt0;
diff --git a/lib/libc/stdio/vfwprintf.c b/lib/libc/stdio/vfwprintf.c
index 4350c48..b75c504 100644
--- a/lib/libc/stdio/vfwprintf.c
+++ b/lib/libc/stdio/vfwprintf.c
@@ -531,8 +531,10 @@ __vfwprintf(FILE *fp, locale_t locale, const wchar_t *fmt0, va_list ap)
 
 
 	/* sorry, fwprintf(read_only_file, L"") returns WEOF, not 0 */
-	if (prepwrite(fp) != 0)
+	if (prepwrite(fp) != 0) {
+		errno = EBADF;
 		return (EOF);
+	}
 
 	convbuf = NULL;
 	fmt = (wchar_t *)fmt0;
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);