1#include "stdio_impl.h"
2#include "locale_impl.h"
3#include <wchar.h>
4#include <limits.h>
5#include <ctype.h>
6#include <string.h>
7
8wint_t ungetwc(wint_t c, FILE *f)
9{
10	unsigned char mbc[MB_LEN_MAX];
11	int l;
12	locale_t *ploc = &CURRENT_LOCALE, loc = *ploc;
13
14	FLOCK(f);
15
16	if (f->mode <= 0) fwide(f, 1);
17	*ploc = f->locale;
18
19	if (!f->rpos) __toread(f);
20	if (!f->rpos || c == WEOF || (l = wcrtomb((void *)mbc, c, 0)) < 0 ||
21	    f->rpos < f->buf - UNGET + l) {
22		FUNLOCK(f);
23		*ploc = loc;
24		return WEOF;
25	}
26
27	if (isascii(c)) *--f->rpos = c;
28	else memcpy(f->rpos -= l, mbc, l);
29
30	f->flags &= ~F_EOF;
31
32	FUNLOCK(f);
33	*ploc = loc;
34	return c;
35}
36