3 files changed, 59 insertions, 5 deletions
diff --git a/src/database/sql/driver/driver.go b/src/database/sql/driver/driver.go
index 1e54b4cf2c..70b3ddc470 100644
--- a/src/database/sql/driver/driver.go
+++ b/src/database/sql/driver/driver.go
@@ -469,7 +469,7 @@ type RowsAffected int64
 var _ Result = RowsAffected(0)
 
 func (RowsAffected) LastInsertId() (int64, error) {
-	return 0, errors.New("no LastInsertId available")
+	return 0, errors.New("LastInsertId is not supported by this driver")
 }
 
 func (v RowsAffected) RowsAffected() (int64, error) {
diff --git a/src/database/sql/sql.go b/src/database/sql/sql.go
index 7537f87d47..7c8d46b100 100644
--- a/src/database/sql/sql.go
+++ b/src/database/sql/sql.go
@@ -1322,11 +1322,13 @@ func (db *DB) putConnDBLocked(dc *driverConn, err error) bool {
 			err:  err,
 		}
 		return true
-	} else if err == nil && !db.closed && db.maxIdleConnsLocked() > len(db.freeConn) {
-		db.freeConn = append(db.freeConn, dc)
+	} else if err == nil && !db.closed {
+		if db.maxIdleConnsLocked() > len(db.freeConn) {
+			db.freeConn = append(db.freeConn, dc)
+			db.startCleanerLocked()
+			return true
+		}
 		db.maxIdleClosed++
-		db.startCleanerLocked()
-		return true
 	}
 	return false
 }
diff --git a/src/database/sql/sql_test.go b/src/database/sql/sql_test.go
index f194744aef..e52091c3af 100644
--- a/src/database/sql/sql_test.go
+++ b/src/database/sql/sql_test.go
@@ -3415,6 +3415,58 @@ func TestConnectionLeak(t *testing.T) {
 	wg.Wait()
 }
 
+func TestStatsMaxIdleClosedZero(t *testing.T) {
+	db := newTestDB(t, "people")
+	defer closeDB(t, db)
+
+	db.SetMaxOpenConns(1)
+	db.SetMaxIdleConns(1)
+	db.SetConnMaxLifetime(0)
+
+	preMaxIdleClosed := db.Stats().MaxIdleClosed
+
+	for i := 0; i < 10; i++ {
+		rows, err := db.Query("SELECT|people|name|")
+		if err != nil {
+			t.Fatal(err)
+		}
+		rows.Close()
+	}
+
+	st := db.Stats()
+	maxIdleClosed := st.MaxIdleClosed - preMaxIdleClosed
+	t.Logf("MaxIdleClosed: %d", maxIdleClosed)
+	if maxIdleClosed != 0 {
+		t.Fatal("expected 0 max idle closed conns, got: ", maxIdleClosed)
+	}
+}
+
+func TestStatsMaxIdleClosedTen(t *testing.T) {
+	db := newTestDB(t, "people")
+	defer closeDB(t, db)
+
+	db.SetMaxOpenConns(1)
+	db.SetMaxIdleConns(0)
+	db.SetConnMaxLifetime(0)
+
+	preMaxIdleClosed := db.Stats().MaxIdleClosed
+
+	for i := 0; i < 10; i++ {
+		rows, err := db.Query("SELECT|people|name|")
+		if err != nil {
+			t.Fatal(err)
+		}
+		rows.Close()
+	}
+
+	st := db.Stats()
+	maxIdleClosed := st.MaxIdleClosed - preMaxIdleClosed
+	t.Logf("MaxIdleClosed: %d", maxIdleClosed)
+	if maxIdleClosed != 10 {
+		t.Fatal("expected 0 max idle closed conns, got: ", maxIdleClosed)
+	}
+}
+
 type nvcDriver struct {
 	fakeDriver
 	skipNamedValueCheck bool