Executing a Broken Statement Causes a Hang

[linden]

Hi,

whenever you try to execute an invalid statement in a transaction an error isn't returned (nor a panic thrown) the program just hangs.

I'd initially noticed this when inserting twice into a table that expected a column to be unique assuming I'd see an error but instead the program just hung.

this does not seem to be directly related to the unique constraint, it seems to happened with any invalid statement; even if they aren't valid SQL.

here's a example:

package main

import (
	"context"
	"log"

	"github.com/tailscale/sqlite/sqliteh"
	"github.com/tailscale/sqlite/sqlitepool"
)

var db *sqlitepool.Pool

func init() {
	var err error

	db, err = sqlitepool.NewPool("file:./db.sqlite", 10, func(init sqliteh.DB) error { return nil }, nil)

	if err != nil {
		panic(err)
	}
}

func main() {
	defer db.Close()

	transaction, err := db.BeginTx(context.Background(), "")

	if err != nil {
		panic(err)
	}

	log.Println("executing invalid statement")

	err = transaction.Exec("this should throw an error")

	if err != nil {
		panic(err)
	}

	log.Println("done")

	err = transaction.Commit()

	if err != nil {
		panic(err)
	}
}

running this program yields the following then hangs forever:

% go run main.go
2023/03/01 22:43:26 executing invalid statement

[linden]

strangely enough: removing defer db.Close() removes the hang and allows transaction.Exec to panic (although, I'd expect an error to be returned, not a panic).

seems this is something to do with the pool being unable to close after an invalid statement?