Some values for displayed_headers trigger a crash upon opening a mail

[lelutin]

I tried setting this:

displayed_headers="From,To,Cc,Bcc,Subject,X-Been-There,X-Loop"

In the hope of seeing mailing list information when it's available. But as it turns out, with this option set this way, when I open any mail I get a traceback with alot frozen on the error:

Traceback (most recent call last):
  File "/usr/bin/alot", line 20, in <module>
    main()
  File "/usr/share/alot/alot/init.py", line 186, in main
    UI(dbman, cmdstring)
  File "/usr/share/alot/alot/ui.py", line 87, in __init__
    self.mainloop.run()
  File "/usr/lib/python2.7/dist-packages/urwid/main_loop.py", line 274, in run
    self.screen.run_wrapper(self._run)
  File "/usr/lib/python2.7/dist-packages/urwid/raw_display.py", line 268, in run_wrapper
    return fn()
  File "/usr/lib/python2.7/dist-packages/urwid/main_loop.py", line 339, in _run
    self.event_loop.run()
  File "/usr/lib/python2.7/dist-packages/urwid/main_loop.py", line 1183, in wrapper
    rval = f(*args,**kargs)
  File "/usr/lib/python2.7/dist-packages/urwid/main_loop.py", line 1142, in _twisted_idle_callback
    callback()
  File "/usr/lib/python2.7/dist-packages/urwid/main_loop.py", line 551, in entering_idle
    self.draw_screen()
  File "/usr/lib/python2.7/dist-packages/urwid/main_loop.py", line 565, in draw_screen
    canvas = self._topmost_widget.render(self.screen_size, focus=True)
  File "/usr/lib/python2.7/dist-packages/urwid/widget.py", line 141, in cached_render
    canv = fn(self, size, focus=focus)
  File "/usr/lib/python2.7/dist-packages/urwid/decoration.py", line 225, in render
    canv = self._original_widget.render(size, focus=focus)
  File "/usr/lib/python2.7/dist-packages/urwid/widget.py", line 141, in cached_render
    canv = fn(self, size, focus=focus)
  File "/usr/lib/python2.7/dist-packages/urwid/container.py", line 1079, in render
    focus and self.focus_part == 'body')
  File "/usr/share/alot/alot/buffers.py", line 406, in render
    return self.body.render(size, focus)
  File "/usr/lib/python2.7/dist-packages/urwid/widget.py", line 141, in cached_render
    canv = fn(self, size, focus=focus)
  File "/usr/lib/python2.7/dist-packages/urwid/widget.py", line 1751, in render
    canv = get_delegate(self).render(size, focus=focus)
  File "/usr/lib/python2.7/dist-packages/urwid/widget.py", line 141, in cached_render
    canv = fn(self, size, focus=focus)
  File "/usr/lib/python2.7/dist-packages/urwid/listbox.py", line 457, in render
    (maxcol, maxrow), focus=focus)
  File "/usr/lib/python2.7/dist-packages/urwid/listbox.py", line 402, in calculate_visible
    next, pos = self.body.get_next( pos )
  File "/usr/share/alot/alot/foreign/urwidtrees/widgets.py", line 80, in get_next
    return self._get(self._tree.next_position(pos))
  File "/usr/share/alot/alot/foreign/urwidtrees/widgets.py", line 67, in _get
    res = self[pos], pos
  File "/usr/share/alot/alot/foreign/urwidtrees/lru_cache.py", line 102, in wrapper
    result = user_function(*args, **kwds)
  File "/usr/share/alot/alot/foreign/urwidtrees/widgets.py", line 53, in __getitem__
    entry = self._tree.get_decorated(pos)
  File "/usr/share/alot/alot/foreign/urwidtrees/nested.py", line 86, in get_decorated
    return self._get_decorated_entry(self._tree, pos)
  File "/usr/share/alot/alot/foreign/urwidtrees/nested.py", line 82, in _get_decorated_entry
    entry = tree.decorate(pos[0], entry, is_first=isf)
  File "/usr/share/alot/alot/foreign/urwidtrees/decoration.py", line 475, in decorate
    line = urwid.Columns(cols, box_columns=range(len(cols))[:-1])
  File "/usr/lib/python2.7/dist-packages/urwid/container.py", line 1761, in __init__
    if focus_column is None and w.selectable():
AttributeError: 'NoneType' object has no attribute 'selectable'

[k0ral]

This issue happens systematically when displaying the Date header in addition to the default ones:

displayed_headers = "From, To, Cc, Bcc, Subject, Date"

Versions:

• alot: 0.8.1
• urwid: 1.3.1
• urwidtrees: 1.0.2

[pazz]

Your log suggests that you're on python version 2.7, whereas alot >0.8 should be python 3 only. Do you get this error on py3 as well?

Just a hunch but it looks as if there is no check wether these headers are present and if not, the widget tree contains unexpected none values..

[k0ral]

Here is a stacktrace with python3:

Traceback (most recent call last):
  File "/nix/store/mxnq8qh6y4mgn95f0xslki5alrd92nwh-python3.7-alot-0.8.1/bin/.alot-wrapped", line 11, in <module>
    sys.exit(main())
  File "/nix/store/mxnq8qh6y4mgn95f0xslki5alrd92nwh-python3.7-alot-0.8.1/lib/python3.7/site-packages/alot/__main__.py", line 137, in main
    UI(dbman, cmdstring)
  File "/nix/store/mxnq8qh6y4mgn95f0xslki5alrd92nwh-python3.7-alot-0.8.1/lib/python3.7/site-packages/alot/ui.py", line 141, in __init__
    self.mainloop.run()
  File "/nix/store/7c7ykw5jr2574d5xcr4v35zzygg7i88g-python3.7-urwid-1.3.1/lib/python3.7/site-packages/urwid/main_loop.py", line 278, in run
    self._run()
  File "/nix/store/7c7ykw5jr2574d5xcr4v35zzygg7i88g-python3.7-urwid-1.3.1/lib/python3.7/site-packages/urwid/main_loop.py", line 376, in _run
    self.event_loop.run()
  File "/nix/store/7c7ykw5jr2574d5xcr4v35zzygg7i88g-python3.7-urwid-1.3.1/lib/python3.7/site-packages/urwid/main_loop.py", line 1186, in run
    raise exc_info[0](exc_info[1]).with_traceback(exc_info[2])
  File "/nix/store/7c7ykw5jr2574d5xcr4v35zzygg7i88g-python3.7-urwid-1.3.1/lib/python3.7/site-packages/urwid/main_loop.py", line 1200, in wrapper
    rval = f(*args,**kargs)
  File "/nix/store/7c7ykw5jr2574d5xcr4v35zzygg7i88g-python3.7-urwid-1.3.1/lib/python3.7/site-packages/urwid/main_loop.py", line 1159, in _twisted_idle_callback
    callback()
  File "/nix/store/7c7ykw5jr2574d5xcr4v35zzygg7i88g-python3.7-urwid-1.3.1/lib/python3.7/site-packages/urwid/main_loop.py", line 564, in entering_idle
    self.draw_screen()
  File "/nix/store/7c7ykw5jr2574d5xcr4v35zzygg7i88g-python3.7-urwid-1.3.1/lib/python3.7/site-packages/urwid/main_loop.py", line 578, in draw_screen
    canvas = self._topmost_widget.render(self.screen_size, focus=True)
  File "/nix/store/7c7ykw5jr2574d5xcr4v35zzygg7i88g-python3.7-urwid-1.3.1/lib/python3.7/site-packages/urwid/widget.py", line 141, in cached_render
    canv = fn(self, size, focus=focus)
  File "/nix/store/7c7ykw5jr2574d5xcr4v35zzygg7i88g-python3.7-urwid-1.3.1/lib/python3.7/site-packages/urwid/decoration.py", line 225, in render
    canv = self._original_widget.render(size, focus=focus)
  File "/nix/store/7c7ykw5jr2574d5xcr4v35zzygg7i88g-python3.7-urwid-1.3.1/lib/python3.7/site-packages/urwid/widget.py", line 141, in cached_render
    canv = fn(self, size, focus=focus)
  File "/nix/store/7c7ykw5jr2574d5xcr4v35zzygg7i88g-python3.7-urwid-1.3.1/lib/python3.7/site-packages/urwid/container.py", line 1083, in render
    focus and self.focus_part == 'body')
  File "/nix/store/mxnq8qh6y4mgn95f0xslki5alrd92nwh-python3.7-alot-0.8.1/lib/python3.7/site-packages/alot/buffers/thread.py", line 128, in render
    return self.body.render(size, focus)
  File "/nix/store/7c7ykw5jr2574d5xcr4v35zzygg7i88g-python3.7-urwid-1.3.1/lib/python3.7/site-packages/urwid/widget.py", line 141, in cached_render
    canv = fn(self, size, focus=focus)
  File "/nix/store/7c7ykw5jr2574d5xcr4v35zzygg7i88g-python3.7-urwid-1.3.1/lib/python3.7/site-packages/urwid/widget.py", line 1750, in render
    canv = get_delegate(self).render(size, focus=focus)
  File "/nix/store/7c7ykw5jr2574d5xcr4v35zzygg7i88g-python3.7-urwid-1.3.1/lib/python3.7/site-packages/urwid/widget.py", line 141, in cached_render
    canv = fn(self, size, focus=focus)
  File "/nix/store/7c7ykw5jr2574d5xcr4v35zzygg7i88g-python3.7-urwid-1.3.1/lib/python3.7/site-packages/urwid/listbox.py", line 455, in render
    (maxcol, maxrow), focus=focus)
  File "/nix/store/7c7ykw5jr2574d5xcr4v35zzygg7i88g-python3.7-urwid-1.3.1/lib/python3.7/site-packages/urwid/listbox.py", line 400, in calculate_visible
    next, pos = self.body.get_next( pos )
  File "/nix/store/5d1hphg56j2rm3a74wchc8ngaqp7g508-python3.7-urwidtrees-1.0.2/lib/python3.7/site-packages/urwidtrees/widgets.py", line 82, in get_next
    return self._get(self._tree.next_position(pos))
  File "/nix/store/5d1hphg56j2rm3a74wchc8ngaqp7g508-python3.7-urwidtrees-1.0.2/lib/python3.7/site-packages/urwidtrees/widgets.py", line 68, in _get
    res = self[pos], pos
  File "/nix/store/5d1hphg56j2rm3a74wchc8ngaqp7g508-python3.7-urwidtrees-1.0.2/lib/python3.7/site-packages/urwidtrees/widgets.py", line 54, in __getitem__
    entry = self._tree.get_decorated(pos)
  File "/nix/store/5d1hphg56j2rm3a74wchc8ngaqp7g508-python3.7-urwidtrees-1.0.2/lib/python3.7/site-packages/urwidtrees/nested.py", line 88, in get_decorated
    return self._get_decorated_entry(self._tree, pos)
  File "/nix/store/5d1hphg56j2rm3a74wchc8ngaqp7g508-python3.7-urwidtrees-1.0.2/lib/python3.7/site-packages/urwidtrees/nested.py", line 84, in _get_decorated_entry
    entry = tree.decorate(pos[0], entry, is_first=isf)
  File "/nix/store/5d1hphg56j2rm3a74wchc8ngaqp7g508-python3.7-urwidtrees-1.0.2/lib/python3.7/site-packages/urwidtrees/decoration.py", line 475, in decorate
    line = urwid.Columns(cols, box_columns=range(len(cols))[:-1])
  File "/nix/store/7c7ykw5jr2574d5xcr4v35zzygg7i88g-python3.7-urwid-1.3.1/lib/python3.7/site-packages/urwid/container.py", line 1765, in __init__
    if focus_column is None and w.selectable():
AttributeError: 'NoneType' object has no attribute 'selectable'