Fix test

pkg/storage/stores/shipper/indexshipper/tsdb/index/index.go

@@ -2248,6 +2248,11 @@ func (dec *Decoder) readSeriesStats(version int, d *encoding.Decbuf, stats **Str
 		return nil
 	}
 
+	// If stats are not requested (stats are nil), we can just skip through the stats
+	if stats == nil {
+		return dec.skipSeriesStats(d)
+	}
+
 	nSMFieldNames := d.Uvarint()
 
 	fields := make(map[string]struct{}, nSMFieldNames)
@@ -2266,6 +2271,14 @@ func (dec *Decoder) readSeriesStats(version int, d *encoding.Decbuf, stats **Str
 	return nil
 }
 
+func (dec *Decoder) skipSeriesStats(d *encoding.Decbuf) error {
+	nSMFieldNames := d.Uvarint()
+	for i := 0; i < nSMFieldNames; i++ {
+		_ = d.Uvarint()
+	}
+	return d.Err()
+}
+
 // prepSeriesBy returns series labels and chunks for a series and only returning selected `by` label names.
 // If `by` is empty, it returns all labels for the series.
 func (dec *Decoder) prepSeriesBy(version int, b []byte, lbls *labels.Labels, chks *[]ChunkMeta, stats **StreamStats, by map[string]struct{}) (*encoding.Decbuf, uint64, error) {