1 files changed, 15 insertions, 9 deletions

diff --git a/lib/libc/stdio/fgetwc.c b/lib/libc/stdio/fgetwc.c
index 0e87753..52bc988 100644
--- a/lib/libc/stdio/fgetwc.c
+++ b/lib/libc/stdio/fgetwc.c
@@ -59,6 +59,7 @@ fgetwc_l(FILE *fp, locale_t locale)
 
 	return (r);
 }
+
 wint_t
 fgetwc(FILE *fp)
 {
@@ -66,40 +67,45 @@ fgetwc(FILE *fp)
 }
 
 /*
- * Non-MT-safe version.
+ * Internal (non-MPSAFE) version of fgetwc().  This version takes an
+ * mbstate_t argument specifying the initial conversion state.  For
+ * wide streams, this should always be fp->_mbstate.  On return, *nread
+ * is set to the number of bytes read.
  */
-wint_t
-__fgetwc(FILE *fp, locale_t locale)
+wint_t 
+__fgetwc_mbs(FILE *fp, mbstate_t *mbs, int *nread, locale_t locale)
 {
 	wchar_t wc;
 	size_t nconv;
 	struct xlocale_ctype *l = XLOCALE_CTYPE(locale);
 
-	if (fp->_r <= 0 && __srefill(fp))
+	if (fp->_r <= 0 && __srefill(fp)) {
+		*nread = 0;
 		return (WEOF);
+	}
 	if (MB_CUR_MAX == 1) {
 		/* Fast path for single-byte encodings. */
 		wc = *fp->_p++;
 		fp->_r--;
+		*nread = 1;
 		return (wc);
 	}
+	*nread = 0;
 	do {
-		nconv = l->__mbrtowc(&wc, fp->_p, fp->_r, &fp->_mbstate);
+		nconv = l->__mbrtowc(&wc, fp->_p, fp->_r, mbs);
 		if (nconv == (size_t)-1)
 			break;
 		else if (nconv == (size_t)-2)
 			continue;
 		else if (nconv == 0) {
-			/*
-			 * Assume that the only valid representation of
-			 * the null wide character is a single null byte.
-			 */
 			fp->_p++;
 			fp->_r--;
+			(*nread)++;
 			return (L'\0');
 		} else {
 			fp->_p += nconv;
 			fp->_r -= nconv;
+			*nread += nconv;
 			return (wc);
 		}
 	} while (__srefill(fp) == 0);