add some guards for nil pointers

1 files changed, 9 insertions, 2 deletions

diff --git a/db.go b/db.go
index 1cfa10f..a37f687 100644
--- a/db.go
+++ b/db.go
@@ -575,8 +575,15 @@ type Stats struct {
 // This is useful when obtaining stats at two different points and time and
 // you need the performance counters that occurred within that time span.
 func (s *Stats) Sub(other *Stats) Stats {
-	var diff Stats = *s
-	diff.TxN = other.TxN - s.TxN
+	var diff Stats
+	if s == nil {
+		return diff
+	}
+	diff = *s
+	if other == nil {
+		return diff
+	}
+	diff.TxN = other.TxN - diff.TxN
 	diff.TxStats = s.TxStats.Sub(&other.TxStats)
 	return diff
 }