Associate a multibyte conversion state object with each stream. Reset it

to the initial state when a stream is opened or seeked upon. Use the
stream's conversion state object instead of a freshly-zeroed one in
fgetwc(), fputwc() and ungetwc().

This is only a performance improvement for now, but it would also be
required in order to support state-dependent encodings.

1 files changed, 2 insertions, 5 deletions

diff --git a/lib/libc/stdio/ungetwc.c b/lib/libc/stdio/ungetwc.c
index 9ef4602..28f873c 100644
--- a/lib/libc/stdio/ungetwc.c
+++ b/lib/libc/stdio/ungetwc.c
@@ -1,5 +1,5 @@
 /*-
- * Copyright (c) 2002 Tim J. Robbins.
+ * Copyright (c) 2002-2004 Tim J. Robbins.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -42,15 +42,12 @@ __FBSDID("$FreeBSD$");
 wint_t
 __ungetwc(wint_t wc, FILE *fp)
 {
-	static const mbstate_t initial;
-	mbstate_t mbs;
 	char buf[MB_LEN_MAX];
 	size_t len;
 
 	if (wc == WEOF)
 		return (WEOF);
-	mbs = initial;
-	if ((len = wcrtomb(buf, wc, &mbs)) == (size_t)-1) {
+	if ((len = wcrtomb(buf, wc, &fp->_extra->mbstate)) == (size_t)-1) {
 		fp->_flags |= __SERR;
 		return (WEOF);
 	}