From e5c285b783f1e8e68f049a5ad5c4d18431dd705b Mon Sep 17 00:00:00 2001
From: Nuno Cruces <ncruces@users.noreply.github.com>
Date: Fri, 28 Mar 2025 11:10:51 +0000
Subject: [PATCH] Discussion #250.

---
 conn.go            | 10 +++++-----
 driver/driver.go   | 11 ++++-------
 tests/conn_test.go |  5 +----
 txn.go             |  3 +++
 4 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/conn.go b/conn.go
index 10d3cd2..7e88d8c 100644
--- a/conn.go
+++ b/conn.go
@@ -343,6 +343,9 @@ func (c *Conn) GetInterrupt() context.Context {
 //
 // https://sqlite.org/c3ref/interrupt.html
 func (c *Conn) SetInterrupt(ctx context.Context) (old context.Context) {
+	if ctx == nil {
+		panic("nil Context")
+	}
 	old = c.interrupt
 	c.interrupt = ctx
 	return old
@@ -406,11 +409,8 @@ func (c *Conn) BusyHandler(cb func(ctx context.Context, count int) (retry bool))
 
 func busyCallback(ctx context.Context, mod api.Module, pDB ptr_t, count int32) (retry int32) {
 	if c, ok := ctx.Value(connKey{}).(*Conn); ok && c.handle == pDB && c.busy != nil {
-		interrupt := c.interrupt
-		if interrupt == nil {
-			interrupt = context.Background()
-		}
-		if interrupt.Err() == nil && c.busy(interrupt, int(count)) {
+		if interrupt := c.interrupt; interrupt.Err() == nil &&
+			c.busy(interrupt, int(count)) {
 			retry = 1
 		}
 	}
diff --git a/driver/driver.go b/driver/driver.go
index 21799ae..871aa74 100644
--- a/driver/driver.go
+++ b/driver/driver.go
@@ -358,13 +358,10 @@ func (c *conn) Commit() error {
 }
 
 func (c *conn) Rollback() error {
-	err := c.Conn.Exec(`ROLLBACK` + c.txReset)
-	if errors.Is(err, sqlite3.INTERRUPT) {
-		old := c.Conn.SetInterrupt(context.Background())
-		defer c.Conn.SetInterrupt(old)
-		err = c.Conn.Exec(`ROLLBACK` + c.txReset)
-	}
-	return err
+	// ROLLBACK even if interrupted.
+	old := c.Conn.SetInterrupt(context.Background())
+	defer c.Conn.SetInterrupt(old)
+	return c.Conn.Exec(`ROLLBACK` + c.txReset)
 }
 
 func (c *conn) Prepare(query string) (driver.Stmt, error) {
diff --git a/tests/conn_test.go b/tests/conn_test.go
index 2c017c0..0ab2405 100644
--- a/tests/conn_test.go
+++ b/tests/conn_test.go
@@ -146,10 +146,7 @@ func TestConn_SetInterrupt(t *testing.T) {
 	}
 	defer stmt.Close()
 
-	go func() {
-		time.Sleep(time.Millisecond)
-		cancel()
-	}()
+	time.AfterFunc(time.Millisecond, cancel)
 
 	// Interrupting works.
 	err = stmt.Exec()
diff --git a/txn.go b/txn.go
index a21b99a..7a5e112 100644
--- a/txn.go
+++ b/txn.go
@@ -20,6 +20,8 @@ type Txn struct {
 }
 
 // Begin starts a deferred transaction.
+// Panics if a transaction is already in-progress.
+// For nested transactions, use [Conn.Savepoint].
 //
 // https://sqlite.org/lang_transaction.html
 func (c *Conn) Begin() Txn {
@@ -119,6 +121,7 @@ func (tx Txn) Commit() error {
 //
 // https://sqlite.org/lang_transaction.html
 func (tx Txn) Rollback() error {
+	// ROLLBACK even if interrupted.
 	return tx.c.exec(`ROLLBACK`)
 }