I'm not sure it's worth updating the text format.  There's already
plenty of disparity between the JSON and text formats, we're
considering deprecating the text format, and, from what I understand,
this might actually break consumers of the text format (the vim
frontend?) since the text format isn't particularly extensible.

Quoth Peter Wang on Aug 05 at  5:22 pm:
> If a leaf part's body content is omitted, return the content length in
> --format=text output, for parity with --format=json output.
> ---
>  notmuch-show.c |   23 +++++++++++++++++++----
>  1 files changed, 19 insertions(+), 4 deletions(-)
> 
> diff --git a/notmuch-show.c b/notmuch-show.c
> index 5c54257..cde8a1e 100644
> --- a/notmuch-show.c
> +++ b/notmuch-show.c
> @@ -488,9 +488,17 @@ format_part_text (const void *ctx, sprinter_t *sp, mime_node_t *node,
>  	GMIME_OBJECT (node->envelope_part) : node->part;
>      GMimeContentType *content_type = g_mime_object_get_content_type (meta);
>      const notmuch_bool_t leaf = GMIME_IS_PART (node->part);
> +    notmuch_bool_t leaf_text_part = FALSE;
>      const char *part_type;
>      int i;
>  
> +    if (leaf &&
> +	g_mime_content_type_is_type (content_type, "text", "*") &&
> +	!g_mime_content_type_is_type (content_type, "text", "html"))
> +    {
> +	leaf_text_part = TRUE;
> +    }
> +
>      if (node->envelope_file) {
>  	notmuch_message_t *message = node->envelope_file;
>  
> @@ -519,7 +527,16 @@ format_part_text (const void *ctx, sprinter_t *sp, mime_node_t *node,
>  	    printf (", Filename: %s", filename);
>  	if (cid)
>  	    printf (", Content-id: %s", cid);
> -	printf (", Content-type: %s\n", g_mime_content_type_to_string (content_type));
> +	printf (", Content-type: %s", g_mime_content_type_to_string (content_type));
> +	if (leaf && !leaf_text_part) {
> +	    GMimeDataWrapper *wrapper = g_mime_part_get_content_object (GMIME_PART (node->part));
> +	    GMimeStream *stream = g_mime_data_wrapper_get_stream (wrapper);
> +	    ssize_t length = g_mime_stream_length (stream);
> +	    if (length >= 0) {
> +		printf (", Content-length: %ld", length);
> +	    }

Same comment about possibly unref'ing wrapper and/or stream.

> +	}
> +	printf ("\n");
>      }
>  
>      if (GMIME_IS_MESSAGE (node->part)) {
> @@ -547,9 +564,7 @@ format_part_text (const void *ctx, sprinter_t *sp, mime_node_t *node,
>      }
>  
>      if (leaf) {
> -	if (g_mime_content_type_is_type (content_type, "text", "*") &&
> -	    !g_mime_content_type_is_type (content_type, "text", "html"))
> -	{
> +	if (leaf_text_part) {
>  	    GMimeStream *stream_stdout = g_mime_stream_file_new (stdout);
>  	    g_mime_stream_file_set_owner (GMIME_STREAM_FILE (stream_stdout), FALSE);
>  	    show_text_part_content (node->part, stream_stdout, 0);