#include	"mail.h"/* Check the consistency of the free list, and return a count of   the number of records on the free list.   This is an undocumented function and should be called when the   mail is not being updated. */int_mail_checkfree(MAIL *mail){	off_t	offset, nextoffset, saveoffset;	char	c, *ptr;	int		count;		/* Read the free list pointer */	saveoffset = FREE_OFF;	offset = _mail_readptr(mail, saveoffset);		/* Loop through the free list */	count = 0;	while (offset != 0) {		count++;		nextoffset = _mail_readidx(mail, offset,FREEIDX);			/* make certain key is all blank */		ptr = mail->idxbuf;		while ( (c = *ptr++) != 0)			if (c != ' ')				return(-1);	/* error */			/* make certain data is all blank */		ptr = _mail_readdat(mail);		while ( (c = *ptr++) != 0)			if (c != ' ')				return(-1);	/* error */		saveoffset = offset;		offset = nextoffset;	}	return(count);		/* can be zero */}