qt wizard: fix offline 2fa wallet creation in some cases

fixes https://github.com/spesmilo/electrum/issues/9037

electrum/gui/qt/__init__.py

@@ -455,7 +455,7 @@ class ElectrumGui(BaseElectrumGui, Logger):
             else:
                 xprv = db.get('x1')['xprv']
             _wiz_data_updates = {
-                'wallet_name': os.path.basename(wallet_file),
+                'wallet_name': wallet_file,
                 'xprv1': xprv,
                 'xpub1': db.get('x1')['xpub'],
                 'xpub2': db.get('x2')['xpub'],

electrum/gui/qt/wizard/wallet.py

@@ -182,6 +182,7 @@ class QENewWalletWizard(NewWalletWizard, QEAbstractWizard, MessageBoxMixin):
         wallet_file = wizard_data['wallet_name']
 
         storage = WalletStorage(wallet_file)
+        assert storage.file_exists(), f"file {wallet_file!r} does not exist"
         if not storage.is_encrypted_with_user_pw() and not storage.is_encrypted_with_hw_device():
             return True
 
@@ -398,6 +399,7 @@ class WCWalletName(WalletWizardComponent, Logger):
             wallet_folder = self.wizard.config.get_datadir_wallet_path()
             self.wizard_data['wallet_name'] = os.path.join(wallet_folder, self.name_e.text())
         else:
+            # FIXME: wizard_data['wallet_name'] is sometimes a full path, sometimes a basename
             self.wizard_data['wallet_name'] = self.name_e.text()
         self.wizard_data['wallet_exists'] = self.wallet_exists
         self.wizard_data['wallet_is_open'] = self.wallet_is_open

electrum/plugins/trustedcoin/qt.py

@@ -489,7 +489,7 @@ class WCShowConfirmOTP(WizardComponent):
         if self.wizard.trustedcoin_qhelper.otpSecret:
             self.secretlabel.setText(self.wizard.trustedcoin_qhelper.otpSecret)
             uri = 'otpauth://totp/Electrum 2FA %s?secret=%s&digits=6' % (
-                self.wizard_data['wallet_name'], self.wizard.trustedcoin_qhelper.otpSecret)
+                os.path.basename(self.wizard_data['wallet_name']), self.wizard.trustedcoin_qhelper.otpSecret)
             self.qr.setData(uri)
 
     def on_busy_changed(self):

electrum/storage.py

@@ -60,6 +60,8 @@ class StorageOnDiskUnexpectedlyChanged(Exception): pass
 # TODO: Rename to Storage
 class WalletStorage(Logger):
 
+    # TODO maybe split this into separate create() and open() classmethods, to prevent some bugs.
+    #      Until then, the onus is on the caller to check file_exists().
     def __init__(self, path):
         Logger.__init__(self)
         self.path = standardize_path(path)