wizard: allow to choose derivation again if script type is not supported (instead of closing the wizard)

lib/base_wizard.py

@@ -31,6 +31,9 @@ from .wallet import Imported_Wallet, Standard_Wallet, Multisig_Wallet, wallet_ty
 from .i18n import _
 
 
+class ScriptTypeNotSupported(Exception): pass
+
+
 class BaseWizard(object):
 
     def __init__(self, config, storage):
@@ -241,15 +244,23 @@ class BaseWizard(object):
             ('legacy BIP44', bip44_derivation(0, False)),
             ('p2sh-segwit BIP49', bip44_derivation(0, True)),
         )
+        while True:
+            try:
                 self.line_dialog(run_next=f, title=_('Derivation'), message=message,
                                  default=default, test=bitcoin.is_bip32_derivation,
                                  presets=presets)
+                return
+            except ScriptTypeNotSupported as e:
+                self.show_error(e)
+                # let the user choose again
 
     def on_hw_derivation(self, name, device_info, derivation):
         from .keystore import hardware_keystore
         xtype = 'p2wpkh-p2sh' if derivation.startswith("m/49'/") else 'standard'
         try:
             xpub = self.plugin.get_xpub(device_info.device.id_, derivation, xtype, self)
+        except ScriptTypeNotSupported:
+            raise  # this is handled in derivation_dialog
         except BaseException as e:
             self.show_error(e)
             return

plugins/digitalbitbox/digitalbitbox.py

@@ -12,6 +12,7 @@ try:
     from electrum.keystore import Hardware_KeyStore
     from ..hw_wallet import HW_PluginBase
     from electrum.util import print_error, to_string, UserCancelled
+    from electrum.base_wizard import ScriptTypeNotSupported
 
     import time
     import hid
@@ -697,6 +698,8 @@ class DigitalBitboxPlugin(HW_PluginBase):
 
 
     def get_xpub(self, device_id, derivation, xtype, wizard):
+        if xtype not in ('standard', 'p2wpkh-p2sh'):
+            raise ScriptTypeNotSupported(_('This type of script is not supported with the Digital Bitbox.'))
         devmgr = self.device_manager()
         client = devmgr.client_by_id(device_id)
         client.handler = self.create_handler(wizard)

plugins/keepkey/plugin.py

@@ -10,6 +10,7 @@ from electrum.i18n import _
 from electrum.plugins import BasePlugin
 from electrum.transaction import deserialize
 from electrum.keystore import Hardware_KeyStore, is_xpubkey, parse_xpubkey
+from electrum.base_wizard import ScriptTypeNotSupported
 
 from ..hw_wallet import HW_PluginBase
 
@@ -208,6 +209,8 @@ class KeepKeyCompatiblePlugin(HW_PluginBase):
         client.used()
 
     def get_xpub(self, device_id, derivation, xtype, wizard):
+        if xtype not in ('standard',):
+            raise ScriptTypeNotSupported(_('This type of script is not supported with KeepKey.'))
         devmgr = self.device_manager()
         client = devmgr.client_by_id(device_id)
         client.handler = wizard