Use Nats-TTL: never for never expires

Signed-off-by: Neil Twigg <[email protected]>

server/jetstream_test.go

@@ -25029,7 +25029,7 @@ func TestJetStreamMessageTTLNeverExpire(t *testing.T) {
 
 	// The first message we publish is set to "never expire", therefore it
 	// won't age out with the MaxAge policy.
-	msg.Header.Set("Nats-TTL", "-1")
+	msg.Header.Set("Nats-TTL", "never")
 	_, err := js.PublishMsg(msg)
 	require_NoError(t, err)
 

server/stream.go

@@ -4215,14 +4215,25 @@ func getMessageTTL(hdr []byte) (int64, error) {
 		return 0, nil
 	}
 	sttl := bytesToString(ttl)
+	if strings.ToLower(sttl) == "never" {
+		return -1, nil
+	}
 	dur, err := time.ParseDuration(sttl)
 	if err == nil {
 		if dur < time.Second {
 			return 0, NewJSMessageTTLInvalidError()
 		}
 		return int64(dur.Seconds()), nil
 	}
-	return parseInt64(ttl), nil
+	t := parseInt64(ttl)
+	if t < 0 {
+		// This probably means a parse failure, hence why
+		// we have a special case "never" for returning -1.
+		// Otherwise we can't know if it's a genuine TTL
+		// that says never expire or if it's a parse error.
+		return 0, NewJSMessageTTLInvalidError()
+	}
+	return t, nil
 }
 
 // Signal if we are clustered. Will acquire rlock.