[PATCH] Fix format_headers_sprinter to return all headers

[Johan Parin <johanparin@gmail.com>]

Modify format_headers_sprinter so that it returns all headers in the
sexp, instead of a fixed set of headers.

This is required in order for the elisp variable
`notmuch-message-headers' to work.

See this bug report:

  https://notmuchmail.org/pipermail/notmuch/2017/026069.html
---
 notmuch-show.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/notmuch-show.c b/notmuch-show.c
index 21792a57..9652ed09 100644
--- a/notmuch-show.c
+++ b/notmuch-show.c
@@ -205,6 +205,15 @@ format_headers_sprinter (sprinter_t *sp, GMimeMessage *message,
     char *recipients_string;
     const char *reply_to_string;
     void *local = talloc_new (sp);
+    GMimeHeaderList *header_list;
+    GMimeHeader *header;
+    int header_count;
+    /* Headers requiring some special treatment in formatting */
+    const char* special_headers[] = {"Subject", "From", "To", "Cc", "Bcc",
+				     "Reply-To", "In-reply-to", "References",
+				     "Date"};
+    const int special_header_count = sizeof(special_headers) / sizeof(char *);
+    bool special;
 
     sp->begin_map (sp);
 
@@ -255,6 +264,24 @@ format_headers_sprinter (sprinter_t *sp, GMimeMessage *message,
 	sp->string (sp, g_mime_message_get_date_string (sp, message));
     }
 
+    header_list  = g_mime_object_get_header_list (GMIME_OBJECT(message));
+    header_count = g_mime_header_list_get_count(header_list);
+
+    for (int i = 0; i < header_count; i++) {
+        header = g_mime_header_list_get_header_at(header_list, i);
+	special = false;
+	for (int k = 0; k < special_header_count; k++)
+	    if (!STRNCMP_LITERAL(g_mime_header_get_name(header),
+				 special_headers[k])) {
+		special = true;
+		break;
+	    }
+	if (special)
+	    continue;
+	sp->map_key (sp, g_mime_header_get_name(header));
+	sp->string (sp, g_mime_header_get_value(header));
+    }
+
     sp->end (sp);
     talloc_free (local);
 }
-- 
2.21.0 (Apple Git-122)