MFC r305241

fgetwc(3) may set both __SEOF and __SERR at once (in case of incomplete
sequence near EOF), so we can't just check for
(wc == WEOF && !__sfeof(fp)) and must relay on __sferror(fp) with
__SERR clearing/restoring.

1 files changed, 11 insertions, 1 deletions

diff --git a/lib/libc/stdio/fgetwln.c b/lib/libc/stdio/fgetwln.c
index 34a80a0..037657c 100644
--- a/lib/libc/stdio/fgetwln.c
+++ b/lib/libc/stdio/fgetwln.c
@@ -47,11 +47,16 @@ fgetwln_l(FILE * __restrict fp, size_t *lenp, locale_t locale)
 {
 	wint_t wc;
 	size_t len;
+	int savserr;
+
 	FIX_LOCALE(locale);
 
 	FLOCKFILE(fp);
 	ORIENT(fp, 1);
 
+	savserr = fp->_flags & __SERR;
+	fp->_flags &= ~__SERR;
+
 	len = 0;
 	while ((wc = __fgetwc(fp, locale)) != WEOF) {
 #define	GROW	512
@@ -64,7 +69,12 @@ fgetwln_l(FILE * __restrict fp, size_t *lenp, locale_t locale)
 		if (wc == L'\n')
 			break;
 	}
-	if (len == 0 || (wc == WEOF && !__sfeof(fp)))
+	/* fgetwc(3) may set both __SEOF and __SERR at once. */
+	if (__sferror(fp))
+		goto error;
+
+	fp->_flags |= savserr;
+	if (len == 0)
 		goto error;
 
 	FUNLOCKFILE(fp);