changing behaviour of notmuch show --part=1

[David Bremner]

Daniel Kahn Gillmor <dkg at fifthhorseman.net> writes:

>>
>> 2) Allow-varying-output: Consider the previous behaviour a bug, fixed by
>>    using gmime-3.0.  This makes it hard for people to rely on, although
>>    how one relies on it currently since it varies by message is a
>>    mystery.
>>
>> 3) Fix the alleged bug: special case the output of the body with
>>    gmime-2.6 to avoid outputting headers.
>
> i favor (2) for the short term, while treating (3) as an open bug to be
> fixed.
>
> thanks for identifying this, David.
>
>        --dkg

(2) is essentially implimented by

    id:20170523005351.15431-3-david at tethera.net

Jeff Stedfast wrote the following code for (3) on the gmime-devel list;
it needs to be conditionalized on GMIME_MAJOR_VERSION, and tested.

,----
| 
|  This is a bit of a hack, but...
| 
|  cache = g_mime_header_list_get_stream (object->headers);
|  g_object_ref (cache);
|  g_mime_header_list_set_stream (object->headers, NULL);
| 
|  g_mime_object_write_to_stream (object, ostream);
| 
|  g_mime_header_list_set_stream (object->headers, cache);
|  g_object_unref (cache);
| 
`----