qol: div-by-zero fix, minor patch on sync (#155)

node/consensus/ceremony/consensus_frames.go

@@ -269,6 +269,22 @@ func (e *CeremonyDataClockConsensusEngine) collect(
 				e.logger.Info("no peers available for sync, waiting")
 				time.Sleep(5 * time.Second)
 			} else if maxFrame > latest.FrameNumber {
+				masterHead, err := e.masterTimeReel.Head()
+				if err != nil {
+					panic(err)
+				}
+
+				if masterHead.FrameNumber < maxFrame {
+					e.logger.Info(
+						"master frame synchronization needed to continue, waiting",
+						zap.Uint64("master_frame_head", masterHead.FrameNumber),
+						zap.Uint64("max_data_frame_target", maxFrame),
+					)
+
+					time.Sleep(30 * time.Second)
+					continue
+				}
+
 				latest, err = e.sync(latest, maxFrame, peerId)
 				if err == nil {
 					break

node/consensus/ceremony/message_handler.go

@@ -347,6 +347,14 @@ func (e *CeremonyDataClockConsensusEngine) handleClockFrameData(
 			}
 		}()
 	}
+
+	head, err := e.dataTimeReel.Head()
+	if err != nil {
+		panic(err)
+	}
+
+	if frame.FrameNumber > head.FrameNumber {
 		e.dataTimeReel.Insert(frame, e.latestFrameReceived < frame.FrameNumber)
+	}
 	return nil
 }

node/consensus/ceremony/peer_messaging.go

@@ -31,6 +31,12 @@ func (e *CeremonyDataClockConsensusEngine) GetDataFrame(
 	var err error
 	if request.FrameNumber == 0 {
 		frame, err = e.dataTimeReel.Head()
+		if frame.FrameNumber == 0 {
+			return nil, errors.Wrap(
+				errors.New("not currently syncable"),
+				"get data frame",
+			)
+		}
 	} else {
 		frame, _, err = e.clockStore.GetDataClockFrame(
 			e.filter,