Temporary Table Persists After Connection Closure

I've encountered an issue where a temporary table is not deleted when its associated database connection is closed. Furthermore, it appears the closed connection is being reused, allowing subsequent users to see the supposedly deleted temporary table from a new database connection. Here's an example to reproduce the problem.

main.go

package main

import (
	"context"
	"database/sql"
	"log"
	"os"

	_ "github.com/mattn/go-sqlite3"
)

func main() {
	err := createTempTableTwice(context.Background())
	if err != nil {
		log.Fatal(err)
	}
	log.Println("Done.")
}

func createTempTableTwice(ctx context.Context) error {
	os.Remove("./foo.db")
	db, err := sql.Open("sqlite3", "./foo.db")
	if err != nil {
		log.Fatal(err)
	}
	defer db.Close()
	{
		conn1, err := db.Conn(ctx)
		if err != nil {
			return err
		}
		_, err = conn1.ExecContext(ctx, `CREATE TEMPORARY TABLE temp.documents(document_id TEXT PRIMARY KEY);`)
		if err != nil {
			return err
		}
		err = conn1.Close()
		if err != nil {
			return err
		}
	}
	conn2, err := db.Conn(ctx)
	if err != nil {
		return err
	}
	defer conn2.Close()
	// NOTE: This line causes the following error: `2025/03/24 15:42:40 table documents already exists`
	_, err = conn2.ExecContext(ctx, `CREATE TEMPORARY TABLE temp.documents(document_id TEXT PRIMARY KEY);`)
	return err
}

go.mod:

module example.com/sqlite-conn-temp-table

go 1.24

require github.com/mattn/go-sqlite3 v1.14.24

Start with the main.go reproduction, especially createTempTableTwice, and run it with github.com/mattn/go-sqlite3 v1.14.24 to confirm the temporary table persists across db.Conn calls. Trace how database/sql connections are closed and reused by the sqlite3 driver; done means the second CREATE TEMPORARY TABLE succeeds without seeing the first connection's table.