Add usual content headers to PGP/MIME signature body part.

 - Enigmail sends them, so it should be good practice to do so too.

2 files changed, 12 insertions, 4 deletions

diff --git a/src/mailman_pgp/pgp/mime.py b/src/mailman_pgp/pgp/mime.py
index f3993a9..02306b4 100644
--- a/src/mailman_pgp/pgp/mime.py
+++ b/src/mailman_pgp/pgp/mime.py
@@ -99,7 +99,7 @@ class MIMEWrapper:
     def is_keys(self):
         for part in walk(self.msg):
             if (not part.is_multipart()
-                    and part.get_content_type() != MIMEWrapper._keys_type):
+                and part.get_content_type() != MIMEWrapper._keys_type):
                 return False
         return True
 
@@ -112,7 +112,7 @@ class MIMEWrapper:
         """
         for part in walk(self.msg):
             if (not part.is_multipart()
-                    and part.get_content_type() == MIMEWrapper._keys_type):
+                and part.get_content_type() == MIMEWrapper._keys_type):
                 return True
         return False
 
@@ -124,7 +124,7 @@ class MIMEWrapper:
         """
         for part in walk(self.msg):
             if (not part.is_multipart()
-                    and part.get_content_type() == MIMEWrapper._keys_type):
+                and part.get_content_type() == MIMEWrapper._keys_type):
                 key, _ = PGPKey.from_blob(part.get_payload())
                 yield key
 
@@ -175,7 +175,13 @@ class MIMEWrapper:
 
         second_part = MIMEApplication(_data=str(signature),
                                       _subtype=MIMEWrapper._signature_subtype,
-                                      _encoder=encode_7or8bit)
+                                      _encoder=encode_7or8bit,
+                                      name='signature.asc')
+        second_part.add_header('content-description',
+                               'OpenPGP digital signature')
+        second_part.add_header('content-disposition', 'attachment',
+                               filename='signature.asc')
+
         out.attach(copy.deepcopy(self.msg))
         out.attach(second_part)
         copy_headers(self.msg, out)
diff --git a/src/mailman_pgp/pgp/utils.py b/src/mailman_pgp/pgp/utils.py
index 1701c63..cc0bda0 100644
--- a/src/mailman_pgp/pgp/utils.py
+++ b/src/mailman_pgp/pgp/utils.py
@@ -20,3 +20,5 @@ def copy_headers(from_msg, to_msg):
     for key, value in from_msg.items():
         if key not in to_msg:
             to_msg[key] = value
+    if to_msg.get_unixfrom() is None:
+        to_msg.set_unixfrom(from_msg.get_unixfrom())