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, 0 deletions

diff --git a/lib/libc/stdio/fseek.c b/lib/libc/stdio/fseek.c
index 2838777..b346b5d 100644
--- a/lib/libc/stdio/fseek.c
+++ b/lib/libc/stdio/fseek.c
@@ -259,6 +259,7 @@ _fseeko(fp, offset, whence, ltest)
 		if (HASUB(fp))
 			FREEUB(fp);
 		fp->_flags &= ~__SEOF;
+		memset(&fp->_extra->mbstate, 0, sizeof(mbstate_t));
 		return (0);
 	}
 
@@ -303,6 +304,7 @@ dumb:
 	fp->_r = 0;
 	/* fp->_w = 0; */	/* unnecessary (I think...) */
 	fp->_flags &= ~__SEOF;
+	memset(&fp->_extra->mbstate, 0, sizeof(mbstate_t));
 	if (ltest && ret > LONG_MAX) {
 		fp->_flags |= __SERR;
 		errno = EOVERFLOW;