fixup! db,pm: avoid redeeming expired tickets

pm/queue.go

@@ -7,6 +7,8 @@ import (
 	"github.com/golang/glog"
 )
 
+const ticketValidityPeriod = 2
+
 // RedeemableEmitter is an interface that describes methods for
 // emitting redeemable tickets
 type RedeemableEmitter interface {
@@ -77,7 +79,7 @@ func (q *ticketQueue) Redeemable() chan *redemption {
 
 // Length returns the current length of the queue
 func (q *ticketQueue) Length() (int, error) {
-	return q.store.WinningTicketCount(q.sender, new(big.Int).Sub(q.tm.LastInitializedRound(), big.NewInt(2)).Int64())
+	return q.store.WinningTicketCount(q.sender, new(big.Int).Sub(q.tm.LastInitializedRound(), big.NewInt(ticketValidityPeriod)).Int64())
 }
 
 // startQueueLoop blocks until the ticket queue is non-empty. When the queue is non-empty
@@ -106,7 +108,7 @@ ticketLoop:
 				continue
 			}
 			for i := 0; i < int(numTickets); i++ {
-				nextTicket, err := q.store.SelectEarliestWinningTicket(q.sender, new(big.Int).Sub(q.tm.LastInitializedRound(), big.NewInt(2)).Int64())
+				nextTicket, err := q.store.SelectEarliestWinningTicket(q.sender, new(big.Int).Sub(q.tm.LastInitializedRound(), big.NewInt(ticketValidityPeriod)).Int64())
 				if err != nil {
 					glog.Errorf("Unable select earliest winning ticket err=%v", err)
 					continue ticketLoop