fix test

Author: kevin-hanselman

progressbar.go

@@ -880,6 +880,11 @@ func (p *ProgressBar) AddMax64(added int64) {
 			p.config.useIECUnits)
 	}
 
+	if p.config.max == -1 {
+		p.lengthUnknown()
+	} else {
+		p.lengthKnown(p.config.max)
+	}
 	p.lock.Unlock() // so p.Add can lock
 
 	p.Add(0) // re-render

progressbar_test.go

@@ -214,9 +214,8 @@ func ExampleProgressBar_ChangeMax() {
 
 func ExampleProgressBar_AddMax() {
 	bar := NewOptions(50, OptionSetWidth(10), OptionSetPredictTime(false))
-	bar.Add(25)
 	bar.AddMax(50)
-	bar.Add(75)
+	bar.Add(100)
 	// Output:
 	// 100% |██████████|
 }