Fixes histograms becoming empty after loaded from checkpoints

vertical-pod-autoscaler/pkg/recommender/util/histogram.go

@@ -277,6 +277,7 @@ func (h *histogram) LoadFromCheckpoint(checkpoint *vpa_types.HistogramCheckpoint
 		h.bucketWeight[bucket] += float64(weight) * ratio
 	}
 	h.totalWeight += checkpoint.TotalWeight
+	h.updateMinAndMaxBucket()
 
 	return nil
 }

vertical-pod-autoscaler/pkg/recommender/util/histogram_test.go

@@ -264,6 +264,21 @@ func TestHistogramLoadFromCheckpointReturnsErrorOnNilInput(t *testing.T) {
 	assert.Error(t, err)
 }
 
+func TestHistogramIsNotEmptyAfterSavingAndLoadingCheckpointsWithBoundaryValues(t *testing.T) {
+	histogram := NewHistogram(testHistogramOptions)
+	histogram.AddSample(1, weightEpsilon, anyTime)
+	histogram.AddSample(2, (float64(MaxCheckpointWeight)*weightEpsilon - weightEpsilon), anyTime)
+	assert.False(t, histogram.IsEmpty())
+
+	checkpoint, err := histogram.SaveToChekpoint()
+	assert.NoError(t, err)
+
+	newHistogram := NewHistogram(testHistogramOptions)
+	err = newHistogram.LoadFromCheckpoint(checkpoint)
+	assert.NoError(t, err)
+	assert.False(t, newHistogram.IsEmpty())
+}
+
 func areUnique(values ...interface{}) bool {
 	dict := make(map[interface{}]bool)
 	for i, v := range values {