#11584: Since __getitem__ returns headers, make decode_header handle them.

Why I consider this a bug rather than an API change: the API change was
to Message, which didn't used to return Headers unless you added them
yourself.  Now it does (for 8bit binary header input), so decode_header
needs to be able to handle them.

1 files changed, 6 insertions, 0 deletions

diff --git a/Lib/email/header.py b/Lib/email/header.py
index 8c32514..2562b30 100644
--- a/Lib/email/header.py
+++ b/Lib/email/header.py
@@ -66,9 +66,15 @@ def decode_header(header):
     otherwise a lower-case string containing the name of the character set
     specified in the encoded string.
 
+    header may be a string that may or may not contain RFC2047 encoded words,
+    or it may be a Header object.
+
     An email.errors.HeaderParseError may be raised when certain decoding error
     occurs (e.g. a base64 decoding exception).
     """
+    # If it is a Header object, we can just return the chunks.
+    if hasattr(header, '_chunks'):
+        return list(header._chunks)
     # If no encoding, just return the header with no charset.
     if not ecre.search(header):
         return [(header, None)]