qml wizard: fix restoring from old mpk (watchonly for "old" seeds)

fixes https://github.com/spesmilo/electrum/issues/8356

electrum/gui/qml/qebitcoin.py

@@ -107,28 +107,27 @@ class QEBitcoin(QObject):
 
     @pyqtSlot(str, str, result=bool)
     def verifyMasterKey(self, key, wallet_type='standard'):
+        # FIXME exceptions raised in here are not well-behaved...
         self.validationMessage = ''
         if not keystore.is_master_key(key):
             self.validationMessage = _('Not a master key')
             return False
 
         k = keystore.from_master_key(key)
-        has_xpub = isinstance(k, keystore.Xpub)
-        assert has_xpub
-        t1 = xpub_type(k.xpub)
-
-        if wallet_type == 'standard':
-            if t1 not in ['standard', 'p2wpkh', 'p2wpkh-p2sh']:
-                self.validationMessage = '%s: %s' % (_('Wrong key type'), t1)
-                return False
-            return True
-        elif wallet_type == 'multisig':
-            if t1 not in ['standard', 'p2wsh', 'p2wsh-p2sh']:
-                self.validationMessage = '%s: %s' % (_('Wrong key type'), t1)
-                return False
-            return True
-
-        raise Exception(f'Unsupported wallet type: {wallet_type}')
+        if isinstance(k, keystore.Xpub):  # has xpub  # TODO are these checks useful?
+            t1 = xpub_type(k.xpub)
+            if wallet_type == 'standard':
+                if t1 not in ['standard', 'p2wpkh', 'p2wpkh-p2sh']:
+                    self.validationMessage = '%s: %s' % (_('Wrong key type'), t1)
+                    return False
+                return True
+            elif wallet_type == 'multisig':
+                if t1 not in ['standard', 'p2wsh', 'p2wsh-p2sh']:
+                    self.validationMessage = '%s: %s' % (_('Wrong key type'), t1)
+                    return False
+                return True
+            raise Exception(f'Unsupported wallet type: {wallet_type}')
+        return True
 
     @pyqtSlot(str, result=bool)
     def verifyDerivationPath(self, path):

electrum/gui/qml/qewizard.py

@@ -108,7 +108,7 @@ class QENewWalletWizard(NewWalletWizard, QEAbstractWizard):
 
             self.createSuccess.emit()
         except Exception as e:
-            self._logger.error(repr(e))
+            self._logger.error(f"createStorage errored: {e!r}")
             self.createError.emit(str(e))
 
 class QEServerConnectWizard(ServerConnectWizard, QEAbstractWizard):

electrum/wizard.py

@@ -381,15 +381,18 @@ class NewWalletWizard(AbstractWizard):
                 raise Exception('unsupported/unknown seed_type %s' % data['seed_type'])
         elif data['keystore_type'] == 'masterkey':
             k = keystore.from_master_key(data['master_key'])
-            has_xpub = isinstance(k, keystore.Xpub)
-            assert has_xpub
-            t1 = xpub_type(k.xpub)
-            if data['wallet_type'] == 'multisig':
-                if t1 not in ['standard', 'p2wsh', 'p2wsh-p2sh']:
-                    raise Exception('wrong key type %s' % t1)
+            if isinstance(k, keystore.Xpub):  # has xpub
+                t1 = xpub_type(k.xpub)
+                if data['wallet_type'] == 'multisig':
+                    if t1 not in ['standard', 'p2wsh', 'p2wsh-p2sh']:
+                        raise Exception('wrong key type %s' % t1)
+                else:
+                    if t1 not in ['standard', 'p2wpkh', 'p2wpkh-p2sh']:
+                        raise Exception('wrong key type %s' % t1)
+            elif isinstance(k, keystore.Old_KeyStore):
+                pass
             else:
-                if t1 not in ['standard', 'p2wpkh', 'p2wpkh-p2sh']:
-                    raise Exception('wrong key type %s' % t1)
+                raise Exception(f"unexpected keystore type: {type(keystore)}")
         else:
             raise Exception('unsupported/unknown keystore_type %s' % data['keystore_type'])