Bugfix

* python/libmu_py/mailbox.c (api_mailbox_create_default): Make name
optional.
* python/mailutils/mailbox.py (MailboxDefault.__init__): Likewise.

@@ -106,7 +106,7 @@ api_mailbox_create_default (PyObject *self, PyObject *args)
   char *name;
   PyMailbox *py_mbox;
 
-  if (!PyArg_ParseTuple (args, "O!s", &PyMailboxType, &py_mbox, &name))
+  if (!PyArg_ParseTuple (args, "O!z", &PyMailboxType, &py_mbox, &name))
     return NULL;
 
   status = mu_mailbox_create_default (&py_mbox->mbox, name);

@@ -203,7 +203,7 @@ class Mailbox (MailboxBase):
         del self.mbox
 
 class MailboxDefault (MailboxBase):
-    def __init__ (self, name):
+    def __init__ (self, name = None):
         self.mbox = mailbox.MailboxType ()
         status = mailbox.create_default (self.mbox, name)
         if status: