From 58d34df29fc327dc8aa8ed79ef4ee1ee52bb58f9 Mon Sep 17 00:00:00 2001
From: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
Date: Mon, 4 Jan 2021 10:10:34 +0100
Subject: [PATCH] imapserver: fix exception handling in xoauth2handler

In case of an exception in XOAUTH2 code refresh (HTTP Error 400: Bad
Request), following exception occurs:

ERROR: While attempting to sync account 'xxx'
  __init__() missing 3 required positional arguments: 'msg', 'hdrs', and 'fp'

Traceback:
  File ".../offlineimap3/offlineimap/accounts.py", line 298, in syncrunner
    self.__sync()
  File ".../offlineimap3/offlineimap/accounts.py", line 374, in __sync
    remoterepos.getfolders()
  File ".../offlineimap3/offlineimap/repository/IMAP.py", line 648, in getfolders
    imapobj = self.imapserver.acquireconnection()
  File ".../offlineimap3/offlineimap/imapserver.py", line 591, in acquireconnection
    self.__authn_helper(imapobj)
  File ".../offlineimap3/offlineimap/imapserver.py", line 448, in __authn_helper
    if func(imapobj):
  File ".../offlineimap3/offlineimap/imapserver.py", line 382, in __authn_xoauth2
    imapobj.authenticate('XOAUTH2', self.__xoauth2handler)
  File ".../offlineimap3/venv/lib/python3.7/site-packages/imaplib2.py", line 682, in authenticate
    typ, dat = self._simple_command('AUTHENTICATE', mechanism.upper())
  File ".../offlineimap3/venv/lib/python3.7/site-packages/imaplib2.py", line 1675, in _simple_command
    return self._command_complete(self._command(name, *args), kw)
  File ".../offlineimap3/venv/lib/python3.7/site-packages/imaplib2.py", line 1395, in _command
    literal = literator(data, rqb)
  File ".../offlineimap3/venv/lib/python3.7/site-packages/imaplib2.py", line 2238, in process
    ret = self.mech(self.decode(data))
  File ".../offlineimap3/offlineimap/imapserver.py", line 257, in __xoauth2handler
    raise type(e)(msg, exc_info()[2])

The exception 'e' is of type HTTPError, which does not have the same kind of
constructor as normal Python exceptions.

Instead, print the constructed message and just raise the existing
exception.

With that change, the same condition triggers another problem further on:

ERROR: While attempting to sync account 'xxx'
  tuple index out of range

Traceback:
  File ".../offlineimap3/offlineimap/accounts.py", line 298, in syncrunner
    self.__sync()
  File ".../offlineimap3/offlineimap/accounts.py", line 374, in __sync
    remoterepos.getfolders()
  File ".../offlineimap3/offlineimap/repository/IMAP.py", line 648, in getfolders
    imapobj = self.imapserver.acquireconnection()
  File ".../offlineimap3/offlineimap/imapserver.py", line 664, in acquireconnection
    elif isinstance(e, socket.error) and e.args[0] == errno.ECONNREFUSED:

because e.args is empty.
---
 offlineimap/imapserver.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/offlineimap/imapserver.py b/offlineimap/imapserver.py
index 0812b3b..3970541 100644
--- a/offlineimap/imapserver.py
+++ b/offlineimap/imapserver.py
@@ -254,7 +254,8 @@ class IMAPServer:
                 except Exception as eparams:
                     msg = "%s [cannot display configuration: %s]" % (e, eparams)
 
-                raise type(e)(msg, exc_info()[2])
+                self.ui.error(msg)
+                raise
             finally:
                 socket.socket = original_socket
 
@@ -660,7 +661,7 @@ class IMAPServer:
                              % (self.hostname, self.repos, e)
                 raise OfflineImapError(reason, severity, exc_info()[2])
 
-            elif isinstance(e, socket.error) and e.args[0] == errno.ECONNREFUSED:
+            elif isinstance(e, socket.error) and e.args and e.args[0] == errno.ECONNREFUSED:
                 # "Connection refused", can be a non-existing port, or an unauthorized
                 # webproxy (open WLAN?)
                 reason = "Connection to host '%s:%d' for repository '%s' was " \