[musl] [PATCH] fgetws: fix checking for fgetwc errors

[Pinghao Wu <xdavidwuph@gmail.com>]

This corrects checking for fgetwc errors by arming dummy errno before
each invocation, and checking errors only if it returns WEOF.
---
 src/stdio/fgetws.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/stdio/fgetws.c b/src/stdio/fgetws.c
index b08b3049..edcd769b 100644
--- a/src/stdio/fgetws.c
+++ b/src/stdio/fgetws.c
@@ -12,18 +12,19 @@ wchar_t *fgetws(wchar_t *restrict s, int n, FILE *restrict f)
 
 	FLOCK(f);
 
-	/* Setup a dummy errno so we can detect EILSEQ. This is
-	 * the only way to catch encoding errors in the form of a
-	 * partial character just before EOF. */
-	errno = EAGAIN;
+	wint_t c;
 	for (; n; n--) {
-		wint_t c = __fgetwc_unlocked(f);
+		/* Setup a dummy errno so we can detect EILSEQ. This is
+		 * the only way to catch encoding errors in the form of a
+		 * partial character just before EOF. */
+		errno = EAGAIN;
+		c = __fgetwc_unlocked(f);
 		if (c == WEOF) break;
 		*p++ = c;
 		if (c == '\n') break;
 	}
 	*p = 0;
-	if (ferror(f) || errno==EILSEQ) p = s;
+	if (c == WEOF && (ferror(f) || errno==EILSEQ)) p = s;
 
 	FUNLOCK(f);
 
-- 
2.35.1