accounts: properly close managed wallets when closing manager (ethereum#28710)

Author: gzliudan

accounts/manager.go

@@ -98,6 +98,9 @@ func NewManager(config *Config, backends ...Backend) *Manager {
 
 // Close terminates the account manager's internal notification processes.
 func (am *Manager) Close() error {
+	for _, w := range am.wallets {
+		w.Close()
+	}
 	errc := make(chan error)
 	am.quit <- errc
 	return <-errc

accounts/usbwallet/wallet.go

@@ -483,6 +483,10 @@ func (w *wallet) Derive(path accounts.DerivationPath, pin bool) (accounts.Accoun
 	w.stateLock.Lock()
 	defer w.stateLock.Unlock()
 
+	if w.device == nil {
+		return accounts.Account{}, accounts.ErrWalletClosed
+	}
+
 	if _, ok := w.paths[address]; !ok {
 		w.accounts = append(w.accounts, account)
 		w.paths[address] = make(accounts.DerivationPath, len(path))