widgets/thread: skip zero-length alternatives

Some systems create multipart/alternative with an empty text/plain part,
with actual content in the text/html part. Pretend the dummy plaintext
part is not there.

1 files changed, 3 insertions, 3 deletions

diff --git a/alot/widgets/thread.py b/alot/widgets/thread.py
index b6eb31d5..68e0ff34 100644
--- a/alot/widgets/thread.py
+++ b/alot/widgets/thread.py
@@ -359,7 +359,7 @@ class _TextPart(_MIMEPartWidget):
         self._w          = urwid.Text(markup_lines)
         self._fold_level = val
 
-class _EmptyMessageWidget(_MIMEPartWidget):
+class _EmptyPartWidget(_MIMEPartWidget):
     def __init__(self):
         body_wgt = urwid.Text('<<< No displayable content >>>', align = 'center')
         super().__init__(body_wgt)
@@ -368,7 +368,7 @@ def _handle_multipart(mime_tree, alternative_pref):
     children = []
     for child in mime_tree.children:
         ch = _render_mime_tree(child, alternative_pref)
-        if ch is not None:
+        if ch is not None and not isinstance(ch, _EmptyPartWidget):
             children.append(ch)
 
     if len(children) > 0:
@@ -396,7 +396,7 @@ def _render_mime_tree(mime_tree, alternative_pref):
     # try rendering the message
     text = mime_tree.render_str()
     if text is not None:
-        return _TextPart(text)
+        return _TextPart(text) if len(text) else _EmptyPartWidget()
 
     body_wgt =  urwid.Text('Undisplayable "%s" MIME part.' % mime_tree.content_type,
                            align = 'center')