mail/envelope: fix setting attachment params

Actually pass them as a tuple of tuples. Also, set the charset param
only for text attachments.

1 files changed, 5 insertions, 1 deletions

diff --git a/alot/mail/envelope.py b/alot/mail/envelope.py
index 4d388aac..ad5f2ee4 100644
--- a/alot/mail/envelope.py
+++ b/alot/mail/envelope.py
@@ -221,6 +221,8 @@ class Envelope:
 
         ctype = helper.guess_mimetype(data)
 
+        params = []
+
         # accept only valid utf-8 as text attachments
         if ctype.partition('/')[0] == 'text':
             try:
@@ -228,11 +230,13 @@ class Envelope:
             except UnicodeDecodeError as e:
                 raise ValueError('Attachment is not valid UTF-8') from e
 
+            params.append(('charset', 'utf-8'))
+
         # Set the filename parameter
         if not filename:
             filename = os.path.basename(path)
 
-        attachment = Attachment(data, ctype, filename, (('charset', 'utf-8')))
+        attachment = Attachment(data, ctype, filename, tuple(params))
         self.attach(attachment)
 
     def attach(self, attachment):