js: remove check of requests pending

Skip 408 errors thrown to client no wait + expires requests

Signed-off-by: Waldemar Quevedo <wally@nats.io>

js.go

@@ -2427,7 +2427,7 @@ var (
 // Returns if the given message is a user message or not, and if
 // `checkSts` is true, returns appropriate error based on the
 // content of the status (404, etc..)
-func checkMsg(msg *Msg, checkSts bool) (usrMsg bool, err error) {
+func checkMsg(msg *Msg, checkSts, isNoWait bool) (usrMsg bool, err error) {
 	// Assume user message
 	usrMsg = true
 
@@ -2457,9 +2457,8 @@ func checkMsg(msg *Msg, checkSts bool) (usrMsg bool, err error) {
 		err = errNoMessages
 	case reqTimeoutSts:
 		// In case of a fetch request with no wait request and expires time,
-		// it will be a 408 error but with a Requests Pending description.
-		desc := msg.Header.Get(descrHdr)
-		if desc == reqPendingDesc {
+		// need to skip 408 errors and retry.
+		if isNoWait {
 			err = errRequestsPending
 		} else {
 			// Older servers may send a 408 when a request in the server was expired
@@ -2582,7 +2581,7 @@ func (sub *Subscription) Fetch(batch int, opts ...PullOpt) ([]*Msg, error) {
 		// or status message, however, we don't care about values of status
 		// messages at this point in the Fetch() call, so checkMsg can't
 		// return an error.
-		if usrMsg, _ := checkMsg(msg, false); usrMsg {
+		if usrMsg, _ := checkMsg(msg, false, false); usrMsg {
 			msgs = append(msgs, msg)
 		}
 	}
@@ -2625,11 +2624,11 @@ func (sub *Subscription) Fetch(batch int, opts ...PullOpt) ([]*Msg, error) {
 			if err == nil {
 				var usrMsg bool
 
-				usrMsg, err = checkMsg(msg, true)
+				usrMsg, err = checkMsg(msg, true, noWait)
 				if err == nil && usrMsg {
 					msgs = append(msgs, msg)
 				} else if noWait && (err == errNoMessages || err == errRequestsPending) && len(msgs) == 0 {
-					// If we have a 404 for our "no_wait" request and have
+					// If we have a 404/408 for our "no_wait" request and have
 					// not collected any message, then resend request to
 					// wait this time.
 					noWait = false

nats.go

@@ -3317,7 +3317,6 @@ const (
 	noResponders       = "503"
 	noMessagesSts      = "404"
 	reqTimeoutSts      = "408"
-	reqPendingDesc     = "Requests Pending"
 	controlMsg         = "100"
 	statusLen          = 3 // e.g. 20x, 40x, 50x
 )