From 21c89003afb004e85ece3e32fee2a0a90d44826e Mon Sep 17 00:00:00 2001
From: Jack Christensen <jack@jackchristensen.com>
Date: Thu, 19 Sep 2019 22:27:12 -0500
Subject: [PATCH] Check if dbSavepoint is already closed

---
 tx.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tx.go b/tx.go
index 0928a2fd..15b6a285 100644
--- a/tx.go
+++ b/tx.go
@@ -241,6 +241,10 @@ func (sp *dbSavepoint) Begin(ctx context.Context) (Tx, error) {
 
 // Commit releases the savepoint essentially committing the pseudo nested transaction.
 func (sp *dbSavepoint) Commit(ctx context.Context) error {
+	if sp.closed {
+		return ErrTxClosed
+	}
+
 	_, err := sp.Exec(ctx, "release savepoint sp_"+strconv.FormatInt(sp.savepointNum, 10))
 	sp.closed = true
 	return err
@@ -250,6 +254,10 @@ func (sp *dbSavepoint) Commit(ctx context.Context) error {
 // ErrTxClosed if the dbSavepoint is already closed, but is otherwise safe to call multiple times. Hence, a defer sp.Rollback()
 // is safe even if sp.Commit() will be called first in a non-error condition.
 func (sp *dbSavepoint) Rollback(ctx context.Context) error {
+	if sp.closed {
+		return ErrTxClosed
+	}
+
 	_, err := sp.Exec(ctx, "rollback to savepoint sp_"+strconv.FormatInt(sp.savepointNum, 10))
 	sp.closed = true
 	return err