memmove(bp, p, tlen);
memcpy(bp, p, tlen);
delete(sp, fm, tm, lmode)	SCR *sp;	MARK *fm, *tm;	int lmode;{	recno_t lno;	size_t blen, len, nlen, tlen;	char *bp, *p;	int eof, rval;	bp = NULL;	/* Case 1 -- delete in line mode. */	if (lmode) {		for (lno = tm->lno; lno >= fm->lno; --lno) {			if (db_delete(sp, lno))				return (1);			++sp->rptlines[L_DELETED];			if (lno % INTERRUPT_CHECK == 0 && INTERRUPTED(sp))				break;		}		goto done;	}	/*	 * Case 2 -- delete to EOF.  This is a special case because it's	 * easier to pick it off than try and find it in the other cases. 	 */	if (db_last(sp, &lno))		return (1);	if (tm->lno >= lno) {		if (tm->lno == lno) {			if (db_get(sp, lno, DBG_FATAL, &p, &len))				return (1);			eof = tm->cno >= len ? 1 : 0;		} else			eof = 1;		if (eof) {			for (lno = tm->lno; lno > fm->lno; --lno) {				if (db_delete(sp, lno))					return (1);				++sp->rptlines[L_DELETED];				if (lno %				    INTERRUPT_CHECK == 0 && INTERRUPTED(sp))					break;			}			if (db_get(sp, fm->lno, DBG_FATAL, &p, &len))				return (1);			GET_SPACE_RET(sp, bp, blen, fm->cno);			memmove(bp, p, fm->cno);			if (db_set(sp, fm->lno, bp, fm->cno))				return (1);			goto done;		}	}	/* Case 3 -- delete within a single line. */	if (tm->lno == fm->lno) {		if (db_get(sp, fm->lno, DBG_FATAL, &p, &len))			return (1);		GET_SPACE_RET(sp, bp, blen, len);		if (fm->cno != 0)			memmove(bp, p, fm->cno);		memmove(bp + fm->cno, p + (tm->cno + 1), len - (tm->cno + 1));		if (db_set(sp, fm->lno,		    bp, len - ((tm->cno - fm->cno) + 1)))			goto err;		goto done;	}	/*	 * Case 4 -- delete over multiple lines.	 *	 * Copy the start partial line into place.	 */	if ((tlen = fm->cno) != 0) {		if (db_get(sp, fm->lno, DBG_FATAL, &p, NULL))			return (1);		GET_SPACE_RET(sp, bp, blen, tlen + 256);		memmove(bp, p, tlen);	}	/* Copy the end partial line into place. */	if (db_get(sp, tm->lno, DBG_FATAL, &p, &len))		goto err;	if (len != 0 && tm->cno != len - 1) {		/*		 * XXX		 * We can overflow memory here, if the total length is greater		 * than SIZE_T_MAX.  The only portable way I've found to test		 * is depending on the overflow being less than the value.		 */		nlen = (len - (tm->cno + 1)) + tlen;		if (tlen > nlen) {			msgq(sp, M_ERR, "002|Line length overflow");			goto err;		}		if (tlen == 0) {			GET_SPACE_RET(sp, bp, blen, nlen);		} else			ADD_SPACE_RET(sp, bp, blen, nlen);		memmove(bp + tlen, p + (tm->cno + 1), len - (tm->cno + 1));		tlen += len - (tm->cno + 1);	}	/* Set the current line. */	if (db_set(sp, fm->lno, bp, tlen))		goto err;	/* Delete the last and intermediate lines. */	for (lno = tm->lno; lno > fm->lno; --lno) {		if (db_delete(sp, lno))			goto err;		++sp->rptlines[L_DELETED];		if (lno % INTERRUPT_CHECK == 0 && INTERRUPTED(sp))			break;	}done:	rval = 0;	if (0)err:		rval = 1;	if (bp != NULL)		FREE_SPACE(sp, bp, blen);	return (rval);}