Allow @ to be recognized as zone origin

t/miek.nl.signed_test

@@ -65,3 +65,4 @@ zzzzz.miek.nl.				      86400 IN RRSIG	NSEC 8 3 86400 20110823011301 20110724011
 a.example.   CLASS32     TYPE731         \# 6 abcd (
                                                ef 01 23 45 )
 b.example.   HS          TYPE62347       \# 0
+@           IN      NS  a.miek.nl.

zscan.go

@@ -167,6 +167,11 @@ func parseZone(r io.Reader, f string, t chan Token, include int) {
 				st = _EXPECT_OWNER_DIR
 			case _OWNER:
 				h.Name = l.token
+                                if l.token == "@" {
+                                        h.Name = origin
+                                        st = _EXPECT_OWNER_BL
+                                        break
+                                }
 				_, ld, ok := IsDomainName(l.token)
 				if !ok {
 					t <- Token{Error: &ParseError{f, "bad owner name", l}}

zscan_rr.go

@@ -748,7 +748,7 @@ func setRFC3597(h RR_Header, c chan lex, f string) (RR, *ParseError) {
 	rr.Hdr = h
 	l := <-c
 	if l.token != "\\#" {
-		return nil, &ParseError{f, "bad RFC3597 Token", l}
+		return nil, &ParseError{f, "Unkown RR type", l}
 	}
 	<-c // _BLANK
 	l = <-c