auto-dnssec maintain and no key: no error message?

[Stephane Bortzmeyer]

On Tue, Jul 30, 2013 at 09:50:46AM -0500,
 Jeremy C. Reed <jreed at isc.org> wrote 
 a message of 7 lines which said:

> > Of course, there is no signature:
> > 
> > % dig +multi @localhost SOA auto.rd.nic.fr
> 
> Add +dnssec

[I thought it was in my .digrc.] It changes nothing. Without a key,
BIND could not create signatures.

% dig +multi +dnssec @localhost SOA auto.rd.nic.fr

; <<>> DiG 9.9.2-P1 <<>> +multi +dnssec @localhost SOA auto.rd.nic.fr
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 13678
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags: do; udp: 4096
;; QUESTION SECTION:
;auto.rd.nic.fr.		IN SOA

;; ANSWER SECTION:
auto.rd.nic.fr.		86400 IN SOA 10.200.0.73. bortzmeyer.nic.fr. (
				2013073000 ; serial
				30480      ; refresh (8 hours 28 minutes)
				26400      ; retry (7 hours 20 minutes)
				2419200    ; expire (4 weeks)
				86400      ; minimum (1 day)
				)

;; AUTHORITY SECTION:
auto.rd.nic.fr.		86400 IN NS ns1.bortzmeyer.org.
auto.rd.nic.fr.		86400 IN NS ns1.auto.rd.nic.fr.

;; ADDITIONAL SECTION:
ns1.auto.rd.nic.fr.	86400 IN A 109.26.74.172

;; Query time: 1 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Tue Jul 30 16:55:24 2013
;; MSG SIZE  rcvd: 167