Read only the AS's objects in RIPE, APNIC and AFRINIC answers (closes #168)

APNIC and RIPE start their answer for an AS with the as-block object of
the block the AS is in. The parser kept the first value of each field
across the whole answer, so it stored the block's dates as the AS's.

The parser now reads an answer from RIPE, APNIC or AFRINIC object by
object. It takes the fields from the aut-num object and the organisation
object it names, and leaves out every other object. The irt object's
address therefore no longer joins the organisation's. ARIN and LACNIC
answers are parsed as before.

Model: opus-5-5

internal/whois/whois_test.go

@@ -51,13 +51,25 @@ source:       IANA
 `
 
 // ripeRecord is RIPE's answer for the AS when asked to leave out person and
-// role objects: the abuse address as a comment, the AS's object and the
+// role objects. It starts with the as-block object of the block the AS is
+// in. Then come the abuse address as a comment, the AS's object and the
 // organisation object it refers to.
 const ripeRecord = `% This is the RIPE Database query service.
 % The objects are in RPSL format.
 
 % Note: --no-personal means ALL personal data has been filtered from this output.
 
+% Information related to 'AS3209 - AS3353'
+
+as-block:       AS3209 - AS3353
+descr:          RIPE NCC ASN block
+remarks:        These AS Numbers are assigned to network operators
+remarks:        in the RIPE NCC service region.
+mnt-by:         RIPE-NCC-HM-MNT
+created:        2018-11-22T15:27:19Z
+last-modified:  2018-11-22T15:27:19Z
+source:         RIPE
+
 % Information related to 'AS3333'
 
 % Abuse contact for 'AS3333' is 'abuse@ripe.net'
@@ -119,6 +131,78 @@ country:        ZA
 address:        1 Example Road
 `
 
+// apnicServer is APNIC's WHOIS server, and apnicASN an AS that APNIC holds.
+const (
+	apnicServer = "whois.apnic.net:43"
+	apnicASN    = 4608
+)
+
+// The keys of the queries LookupASN sends for apnicASN: IANA's, then
+// APNIC's, which asks APNIC to leave out person and role objects.
+const (
+	apnicIANAQuery = ianaServer + " AS4608"
+	apnicQuery     = apnicServer + " --no-personal AS4608"
+)
+
+// apnicRecord is APNIC's answer for apnicASN when asked to leave out person
+// and role objects, shortened. It starts with the as-block object of the
+// block the AS is in. Then come the abuse address as a comment, the AS's
+// object, and the irt and organisation objects it refers to.
+const apnicRecord = `% [whois.apnic.net]
+% Whois data copyright terms    http://www.apnic.net/db/dbcopyright.html
+
+% Note: --no-personal means ALL personal data has been filtered from this output.
+
+% Information related to 'AS4608 - AS4865'
+
+as-block:       AS4608 - AS4865
+descr:          APNIC ASN block
+remarks:        These AS numbers are further assigned by APNIC
+remarks:        to APNIC members and end-users in the APNIC region
+mnt-by:         APNIC-HM
+mnt-lower:      APNIC-HM
+last-modified:  2019-05-20T03:52:26Z
+source:         APNIC
+
+% Information related to 'AS4608'
+
+% Abuse contact for 'AS4608' is 'abuse@apnic.net'
+
+aut-num:        AS4608
+as-name:        APNIC-SERVICES
+descr:          Asia Pacific Network Information Centre
+country:        AU
+org:            ORG-APNI1-AP
+admin-c:        AIC1-AP
+abuse-c:        AA1589-AP
+mnt-by:         APNIC-HM
+mnt-irt:        IRT-APNIC-IS-AP
+last-modified:  2026-08-26T00:40:00Z
+source:         APNIC
+
+irt:            IRT-APNIC-IS-AP
+address:        South Brisbane, Australia
+e-mail:         helpdesk@apnic.net
+abuse-mailbox:  abuse@apnic.net
+mnt-by:         MAINT-APNIC-IS-AP
+last-modified:  2025-11-18T00:27:08Z
+source:         APNIC
+
+organisation:   ORG-APNI1-AP
+org-name:       Asia Pacific Network Information Centre
+org-type:       LIR
+country:        AU
+address:        PO Box 3646
+address:        South Brisbane, QLD 4101,
+address:        Australia
+e-mail:         noc@apnic.net
+mnt-by:         APNIC-HM
+last-modified:  2026-08-24T12:58:43Z
+source:         APNIC
+
+% This query was served by the APNIC Whois Service version 1.88.48 (WHOIS-UK2)
+`
+
 // ianaPrivateUse is IANA's answer for a private-use AS: its block and no
 // referral.
 const ianaPrivateUse = `% IANA WHOIS server
@@ -198,7 +282,8 @@ func lookUp(
 // answers only a query that leaves out person and role objects, and its
 // answer to that still fills the AS's fields: the abuse address from the
 // comment line, and the organisation's name and country from its object.
-// The dates are the AS's: IANA's "changed:" line dates its block.
+// The dates are the AS's. IANA's "changed:" line dates the AS's block, and
+// so do the dates of the as-block object at the start of RIPE's answer.
 func TestLookupASNReadsTheRIRAnswer(t *testing.T) {
 	t.Parallel()
 
@@ -238,6 +323,46 @@ func TestLookupASNReadsTheRIRAnswer(t *testing.T) {
 	}
 }
 
+// TestLookupASNReadsOnlyTheASAndItsOrganisation looks up an AS at APNIC,
+// whose answer starts with the as-block object of the block the AS is in.
+// The last-modified date is the aut-num object's, not the block's. The
+// address is the organisation object's alone, without the irt object's.
+func TestLookupASNReadsOnlyTheASAndItsOrganisation(t *testing.T) {
+	t.Parallel()
+
+	client := whois.NewClient()
+	client.DialContext = fakeServers(t, map[string]string{
+		apnicIANAQuery: "refer:        whois.apnic.net\n",
+		apnicQuery:     apnicRecord,
+	})
+
+	info, err := client.LookupASN(t.Context(), apnicASN)
+	if err != nil {
+		t.Fatalf("LookupASN: %v", err)
+	}
+
+	wantLastMod := time.Date(2026, 8, 26, 0, 40, 0, 0, time.UTC)
+	if info.LastMod == nil || !info.LastMod.Equal(wantLastMod) {
+		t.Errorf("LookupASN last modified = %v, want %v",
+			info.LastMod, wantLastMod)
+	}
+
+	got := []string{
+		info.ASName, info.OrgID, info.OrgName, info.CountryCode,
+		info.Address, info.AbuseEmail,
+	}
+	want := []string{
+		"APNIC-SERVICES", "ORG-APNI1-AP",
+		"Asia Pacific Network Information Centre", "AU",
+		"PO Box 3646\nSouth Brisbane, QLD 4101,\nAustralia", "abuse@apnic.net",
+	}
+
+	if !slices.Equal(got, want) {
+		t.Errorf("LookupASN = AS name, org ID, org name, country, address, "+
+			"abuse address %q; want %q", got, want)
+	}
+}
+
 // TestLookupASNAsksAPNICAndAFRINICToLeaveOutPersonalData looks up an AS at
 // APNIC and at AFRINIC. Each answers only a query that leaves out person
 // and role objects, as RIPE does. That one answer still holds the