progress: Overall ETA never less than max ETA

progress/render.go

@@ -70,10 +70,14 @@ func (p *Progress) extractDoneAndActiveTrackers() ([]*Tracker, []*Tracker) {
 	var trackersActive, trackersDone []*Tracker
 	var activeTrackersProgress int64
 	p.trackersActiveMutex.RLock()
+	var maxETA time.Duration
 	for _, tracker := range p.trackersActive {
 		if !tracker.IsDone() {
 			trackersActive = append(trackersActive, tracker)
 			activeTrackersProgress += int64(tracker.PercentDone())
+			if eta := tracker.ETA(); eta > maxETA {
+				maxETA = eta
+			}
 		} else {
 			trackersDone = append(trackersDone, tracker)
 		}
@@ -85,6 +89,7 @@ func (p *Progress) extractDoneAndActiveTrackers() ([]*Tracker, []*Tracker) {
 	// calculate the overall tracker's progress value
 	p.overallTracker.value = int64(p.LengthDone()+len(trackersDone)) * 100
 	p.overallTracker.value += activeTrackersProgress
+	p.overallTracker.minETA = maxETA
 	if len(trackersActive) == 0 {
 		p.overallTracker.MarkAsDone()
 	}

progress/tracker.go

@@ -35,6 +35,7 @@ type Tracker struct {
 	timeStart time.Time
 	timeStop  time.Time
 	value     int64
+	minETA    time.Duration
 }
 
 // ETA returns the expected time of "arrival" or completion of this tracker. It
@@ -56,7 +57,11 @@ func (t *Tracker) ETA() time.Duration {
 	if pDone == 0 {
 		return time.Duration(0)
 	}
-	return time.Duration((int64(timeTaken) / pDone) * (100 - pDone))
+	eta := time.Duration((int64(timeTaken) / pDone) * (100 - pDone))
+	if eta < t.minETA {
+		eta = t.minETA
+	}
+	return eta
 }
 
 // Increment updates the current value of the task being tracked.