(authenticate_imap_select): Use

ENOSYS as the default status value to allow MU_ERR_AUTH_FAILURE
to be propagated back to the caller.
(imap_parse): Display "NO/Bad Tagged" error diagnostics only if
status != MU_ERR_AUTH_FAILURE. Should we display it at all?

@@ -372,9 +372,9 @@ authenticate_imap_select (authority_t auth)
   folder_t folder = authority_get_owner (auth);
   f_imap_t f_imap = folder->data;
   struct auth_tab *p;
-  int status = MU_ERR_AUTH_FAILURE;
+  int status = ENOSYS;
   
-  for (p = auth_tab; status && p->name; p++)
+  for (p = auth_tab; status == ENOSYS && p->name; p++)
     {
       f_imap->state = IMAP_AUTH;
       status = p->method (auth);
@@ -2475,10 +2475,12 @@ imap_parse (f_imap_t f_imap)
 		  status = MU_ERR_AUTH_FAILURE;
 		}
 	      else
+		{
 		  status = EINVAL;
 		  mu_error ("NO/Bad Tagged: %s %s\n", response, remainder);
 		}
 	    }
+	}
       f_imap->ptr = f_imap->buffer;
     }