From 3bce691e38b77726b86671170492b3c85c61b3af Mon Sep 17 00:00:00 2001
From: Alberto Carretero <angelalbertoc.r@gmail.com>
Date: Mon, 23 Oct 2023 15:28:47 +0200
Subject: [PATCH] bugfix: after executing statement table lock was not cleared

When we execute a statement, we step once and return. If the query
returned more than one row, we would not have consumed everything so the
underlying table would still be locked even when the execution had
finished.

This change resets the statement after execution so that the locks can
be cleared.
---
 sqlite3.go      |  6 ++++++
 sqlite3_test.go | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/sqlite3.go b/sqlite3.go
index 5e4e2ff5..86387c24 100644
--- a/sqlite3.go
+++ b/sqlite3.go
@@ -2083,6 +2083,12 @@ func (s *SQLiteStmt) execSync(args []driver.NamedValue) (driver.Result, error) {
 		return nil, err
 	}
 
+	rv = C.sqlite3_reset(s.s)
+	if rv != C.SQLITE_OK {
+		err := s.c.lastError()
+		C.sqlite3_clear_bindings(s.s)
+		return nil, err
+	}
 	return &SQLiteResult{id: int64(rowid), changes: int64(changes)}, nil
 }
 
diff --git a/sqlite3_test.go b/sqlite3_test.go
index 326361ec..30d61564 100644
--- a/sqlite3_test.go
+++ b/sqlite3_test.go
@@ -2101,6 +2101,7 @@ var tests = []testing.InternalTest{
 	{Name: "TestManyQueryRow", F: testManyQueryRow},
 	{Name: "TestTxQuery", F: testTxQuery},
 	{Name: "TestPreparedStmt", F: testPreparedStmt},
+	{Name: "TestExecStmtDoesNotBlockTable", F: testExecStmtDoesNotBlockTable},
 	{Name: "TestExecEmptyQuery", F: testExecEmptyQuery},
 }
 
@@ -2432,6 +2433,40 @@ func testPreparedStmt(t *testing.T) {
 	wg.Wait()
 }
 
+// testExecStmtDoesNotBlockTable tests that the tables' locks are cleared after
+// executing a statement.
+func testExecStmtDoesNotBlockTable(t *testing.T) {
+	db.tearDown()
+	db.mustExec("CREATE TABLE t (count INT)")
+	sel, err := db.Prepare("SELECT count FROM t")
+	if err != nil {
+		t.Fatalf("prepare 1: %v", err)
+	}
+	ins, err := db.Prepare(db.q("INSERT INTO t (count) VALUES (?)"))
+	if err != nil {
+		t.Fatalf("prepare 2: %v", err)
+	}
+	drop, err := db.Prepare(db.q("DROP TABLE t"))
+	if err != nil {
+		t.Fatalf("prepare 3: %v", err)
+	}
+
+	for n := 1; n <= 3; n++ {
+		if _, err := ins.Exec(n); err != nil {
+			t.Fatalf("insert(%d) = %v", n, err)
+		}
+	}
+
+	_, err = sel.Exec()
+	if err != nil {
+		t.Fatalf("exec 1: %v", err)
+	}
+	_, err = drop.Exec()
+	if err != nil {
+		t.Fatalf("exec 2: %v", err)
+	}
+}
+
 // testEmptyQuery is test for validating the API in case of empty query
 func testExecEmptyQuery(t *testing.T) {
 	db.tearDown()