1#include "stdio_impl.h"
 2
 3int __overflow(FILE *f, int _c)
 4{
 5	unsigned char c = _c;
 6	if (!f->wend && __towrite(f)) return EOF;
 7	if (f->wpos != f->wend && c != f->lbf) return *f->wpos++ = c;
 8	if (f->write(f, &c, 1)!=1) return EOF;
 9	return c;
10}