close #4102

close #3337

lib/storage.py

@@ -51,6 +51,8 @@ FINAL_SEED_VERSION = 16     # electrum >= 2.7 will set this to prevent
 def multisig_type(wallet_type):
     '''If wallet_type is mofn multi-sig, return [m, n],
     otherwise return None.'''
+    if not wallet_type:
+        return None
     match = re.match('(\d+)of(\d+)', wallet_type)
     if match:
         match = [int(x) for x in match.group(1, 2)]
@@ -417,7 +419,7 @@ class WalletStorage(PrintError):
                     d['seed'] = seed
                 self.put(key, d)
         else:
-            raise
+            raise Exception('Unable to tell wallet type. Is this even a wallet file?')
         # remove junk
         self.put('master_public_key', None)
         self.put('master_public_keys', None)

lib/wallet.py

@@ -2301,5 +2301,5 @@ class Wallet(object):
             return Multisig_Wallet
         if wallet_type in wallet_constructors:
             return wallet_constructors[wallet_type]
-        raise RuntimeError("Unknown wallet type: " + wallet_type)
+        raise RuntimeError("Unknown wallet type: " + str(wallet_type))