IndexError from _header_value_parser.py

[josch]

This problem occurs with alot from git. Steps to reproduce:

Consider this email:

To: foo <foo@bar.com>, 
From: baz <baz@blub.de>
Message-ID: <spamtest@spamtest.com>
Subject: test
Date: Sun, 09 Apr 2017 21:24:04 +0200

foobar

md5sum is 88473fa33cf507f2924f6ecdbee32fd9

If I try opening the thread of that mail in alot I get:

DEBUG:ui:fire first command
DEBUG:ui:global command string: "search id:spamtest@spamtest.com"
DEBUG:__init__:mode:global got commandline "search id:spamtest@spamtest.com"
DEBUG:__init__:ARGS: ['search', 'id:spamtest@spamtest.com']
DEBUG:__init__:cmd parms {'sort': None, 'query': ['id:spamtest@spamtest.com']}
DEBUG:manager:Worker process 13358 spawned
DEBUG:manager:Worker process 13358 exited successfully
DEBUG:utils:unquoted header: |baz <baz@blub.de>|
DEBUG:utils:Content-Transfer-Encoding: "7bit"
DEBUG:utils:assuming Content-Transfer-Encoding: 7bit
DEBUG:walker:EMPTY PIPE
DEBUG:ui:Got key (['enter'], [10])
DEBUG:ui:cmdline: 'select'
DEBUG:ui:search command string: "select"
DEBUG:__init__:mode:search got commandline "select"
DEBUG:__init__:ARGS: ['select']
DEBUG:__init__:cmd parms {}
INFO:search:open thread view for thread:0000000000036cfe: test
DEBUG:utils:unquoted header: |baz <baz@blub.de>|
DEBUG:utils:unquoted header: |baz <baz@blub.de>|
ERROR:ui:Traceback (most recent call last):
  File "/home/josch/git/alot/alot/ui.py", line 711, in apply_command
    cmd.apply(self)
  File "/home/josch/git/alot/alot/commands/search.py", line 41, in apply
    sb = buffers.ThreadBuffer(ui, self.thread)
  File "/home/josch/git/alot/alot/buffers/thread.py", line 37, in __init__
    self.rebuild()
  File "/home/josch/git/alot/alot/buffers/thread.py", line 73, in rebuild
    self._tree = ThreadTree(self.thread)
  File "/home/josch/git/alot/alot/widgets/thread.py", line 352, in __init__
    accumulate(msg)
  File "/home/josch/git/alot/alot/widgets/thread.py", line 331, in accumulate
    self._message[mid] = MessageTree(msg, odd)
  File "/home/josch/git/alot/alot/widgets/thread.py", line 172, in __init__
    self._maintree = SimpleTree(self._assemble_structure())
  File "/home/josch/git/alot/alot/widgets/thread.py", line 199, in _assemble_structure
    mainstruct.append((self._get_headers(), None))
  File "/home/josch/git/alot/alot/widgets/thread.py", line 255, in _get_headers
    headers)
  File "/home/josch/git/alot/alot/widgets/thread.py", line 283, in construct_header_pile
    values = mail.get_all(key)
  File "/usr/lib/python3.7/email/message.py", line 510, in get_all
    values.append(self.policy.header_fetch_parse(k, v))
  File "/usr/lib/python3.7/email/policy.py", line 162, in header_fetch_parse
    return self.header_factory(name, value)
  File "/usr/lib/python3.7/email/headerregistry.py", line 589, in __call__
    return self[name](name, value)
  File "/usr/lib/python3.7/email/headerregistry.py", line 197, in __new__
    cls.parse(value, kwds)
  File "/usr/lib/python3.7/email/headerregistry.py", line 340, in parse
    kwds['parse_tree'] = address_list = cls.value_parser(value)
  File "/usr/lib/python3.7/email/headerregistry.py", line 331, in value_parser
    address_list, value = parser.get_address_list(value)
  File "/usr/lib/python3.7/email/_header_value_parser.py", line 1930, in get_address_list
    token, value = get_address(value)
  File "/usr/lib/python3.7/email/_header_value_parser.py", line 1907, in get_address
    token, value = get_group(value)
  File "/usr/lib/python3.7/email/_header_value_parser.py", line 1863, in get_group
    token, value = get_display_name(value)
  File "/usr/lib/python3.7/email/_header_value_parser.py", line 1689, in get_display_name
    token, value = get_phrase(value)
  File "/usr/lib/python3.7/email/_header_value_parser.py", line 1364, in get_phrase
    token, value = get_word(value)
  File "/usr/lib/python3.7/email/_header_value_parser.py", line 1339, in get_word
    if value[0]=='"':
IndexError: string index out of range

The problem goes away when I remove the trailing space in the To field.

[pazz]

This very much looks like a bug in the email lib.
Can you reproduce this directly on the email, i.e., create an email.Message from your string and call get_all('To')?