From 443c402f60b5c1ee442aa5ba932ae2fe77b3bb44 Mon Sep 17 00:00:00 2001
From: Brian Warner <warner@lothar.com>
Date: Mon, 1 Jan 2018 16:56:18 +0100
Subject: [PATCH] remove WormholeClosedError, simplify control paths in
 cmd_send/receive

lgtm.com noticed some unreachable code paths, and it turns out that nothing
in the rest of the code base could ever raise WormholeClosedError (I guess it
was leftover from before the big API refactoring). Both sender and receiver
are simpler without the unnecessary checks and state variables.
---
 src/wormhole/cli/cmd_receive.py | 10 ++--------
 src/wormhole/cli/cmd_send.py    | 12 +++---------
 src/wormhole/errors.py          |  3 ---
 3 files changed, 5 insertions(+), 20 deletions(-)

diff --git a/src/wormhole/cli/cmd_receive.py b/src/wormhole/cli/cmd_receive.py
index d9ba896..03357ca 100644
--- a/src/wormhole/cli/cmd_receive.py
+++ b/src/wormhole/cli/cmd_receive.py
@@ -7,7 +7,7 @@ from twisted.internet.defer import inlineCallbacks, returnValue
 from twisted.python import log
 from wormhole import create, input_with_completion, __version__
 from ..transit import TransitReceiver
-from ..errors import TransferError, WormholeClosedError
+from ..errors import TransferError
 from ..util import (dict_to_bytes, bytes_to_dict, bytes_to_hexstr,
                     estimate_free_space)
 from .welcome import handle_welcome
@@ -152,15 +152,9 @@ class Receiver:
         self._show_verifier(verifier_bytes)
 
         want_offer = True
-        done = False
 
         while True:
-            try:
-                them_d = yield self._get_data(w)
-            except WormholeClosedError:
-                if done:
-                    returnValue(None)
-                raise TransferError("unexpected close")
+            them_d = yield self._get_data(w)
             #print("GOT", them_d)
             recognized = False
             if u"transit" in them_d:
diff --git a/src/wormhole/cli/cmd_send.py b/src/wormhole/cli/cmd_send.py
index adec1e2..0e5c4e5 100644
--- a/src/wormhole/cli/cmd_send.py
+++ b/src/wormhole/cli/cmd_send.py
@@ -6,7 +6,7 @@ from twisted.python import log
 from twisted.protocols import basic
 from twisted.internet import reactor
 from twisted.internet.defer import inlineCallbacks, returnValue
-from ..errors import (TransferError, WormholeClosedError, UnsendableFileError)
+from ..errors import TransferError, UnsendableFileError
 from wormhole import create, __version__
 from ..transit import TransitSender
 from ..util import dict_to_bytes, bytes_to_dict, bytes_to_hexstr
@@ -169,15 +169,9 @@ class Sender:
         self._send_data({"offer": offer}, w)
 
         want_answer = True
-        done = False
 
         while True:
-            try:
-                them_d_bytes = yield w.get_message()
-            except WormholeClosedError:
-                if done:
-                    returnValue(None)
-                raise TransferError("unexpected close")
+            them_d_bytes = yield w.get_message()
             # TODO: get_message() fired, so get_verifier must have fired, so
             # now it's safe to use w.derive_key()
             them_d = bytes_to_dict(them_d_bytes)
@@ -193,8 +187,8 @@ class Sender:
                 recognized = True
                 if not want_answer:
                     raise TransferError("duplicate answer")
+                want_answer = True
                 yield self._handle_answer(them_d[u"answer"])
-                done = True
                 returnValue(None)
             if not recognized:
                 log.msg("unrecognized message %r" % (them_d,))
diff --git a/src/wormhole/errors.py b/src/wormhole/errors.py
index 8d191b1..8bd9718 100644
--- a/src/wormhole/errors.py
+++ b/src/wormhole/errors.py
@@ -61,9 +61,6 @@ class ReflectionAttack(WormholeError):
 class InternalError(WormholeError):
     """The programmer did something wrong."""
 
-class WormholeClosedError(InternalError):
-    """API calls may not be made after close() is called."""
-
 class TransferError(WormholeError):
     """Something bad happened and the transfer failed."""