bugfix: missing account close in queue direct send

found while writing new tests for upcoming functionality.
the test had an embarrassing workaround for the symptoms...

queue/direct.go

@@ -728,6 +728,10 @@ func updateRecipientDomainTLS(ctx context.Context, log mlog.Log, senderAccount s
 	if err != nil {
 		return fmt.Errorf("open account: %w", err)
 	}
+	defer func() {
+		err := acc.Close()
+		log.Check(err, "closing account")
+	}()
 	err = acc.DB.Write(ctx, func(tx *bstore.Tx) error {
 		// First delete any existing record.
 		if err := tx.Delete(&store.RecipientDomainTLS{Domain: rdt.Domain}); err != nil && err != bstore.ErrAbsent {

queue/queue_test.go

@@ -49,20 +49,10 @@ func tcompare(t *testing.T, got, exp any) {
 	}
 }
 
-var keepAccount bool
-
 func setup(t *testing.T) (*store.Account, func()) {
 	// Prepare config so email can be delivered to mjl@mox.example.
 
-	// Don't trigger the account consistency checks. Only remove account files on first
-	// (of randomized) runs.
-	if !keepAccount {
-		os.RemoveAll("../testdata/queue/data")
-		keepAccount = true
-	} else {
-		os.RemoveAll("../testdata/queue/data/queue")
-	}
-
+	os.RemoveAll("../testdata/queue/data")
 	log := mlog.New("queue", nil)
 	mox.Context = ctxbg
 	mox.ConfigStaticPath = filepath.FromSlash("../testdata/queue/mox.conf")
@@ -75,6 +65,7 @@ func setup(t *testing.T) (*store.Account, func()) {
 	mox.Shutdown, mox.ShutdownCancel = context.WithCancel(ctxbg)
 	return acc, func() {
 		acc.Close()
+		acc.CheckClosed()
 		mox.ShutdownCancel()
 		mox.Shutdown, mox.ShutdownCancel = context.WithCancel(ctxbg)
 		Shutdown()

store/account.go

@@ -1059,6 +1059,15 @@ func initAccount(db *bstore.DB) error {
 	})
 }
 
+// CheckClosed asserts that the account has a zero reference count. For use in tests.
+func (a *Account) CheckClosed() {
+	openAccounts.Lock()
+	defer openAccounts.Unlock()
+	if a.nused != 0 {
+		panic(fmt.Sprintf("account still in use, %d refs", a.nused))
+	}
+}
+
 // Close reduces the reference count, and closes the database connection when
 // it was the last user.
 func (a *Account) Close() error {