* add support for message-references:

- mu_msg_get_references and mu_msg_get_references_str get the list of
    refences ("References:" and "In-reply-to:") as a GList,
    resp. comma-separated list
  - stored in database as a value, can be shown in mu find output using 'r'
    (db needs rebuild)
  - document in mu-find manpage

man/mu-find.1

@@ -1,4 +1,4 @@
-.TH MU FIND 1 "March 2011" "User Manuals"
+.TH MU FIND 1 "April 2011" "User Manuals"
 
 .SH NAME 
 
@@ -273,6 +273,7 @@ search parameters; the complete list:
 	s	Message \fBs\fRubject
 	i	Message-\fBi\fRd
 	m	\fBm\fRaildir
+	r       \fBr\fReferences (message ids In-reply-to, References as comma-separated list)
 .fi
 
 

src/mu-msg-fields.c

@@ -158,6 +158,13 @@ static const MuMsgField FIELD_DATA[] = {
 		MU_MSG_FIELD_TYPE_TIME_T,
 		"timestamp", 'x', 0,
 		FLAG_GMIME 
+	},
+
+	{ 
+		MU_MSG_FIELD_ID_REFS,
+		MU_MSG_FIELD_TYPE_STRING,
+		"refs", 'r', 'R',
+		FLAG_GMIME | FLAG_XAPIAN_VALUE
 	}
 };
 

src/mu-msg-fields.h

@@ -41,7 +41,8 @@ enum _MuMsgFieldId {
 	MU_MSG_FIELD_ID_TO,
 	MU_MSG_FIELD_ID_MSGID,
 	MU_MSG_FIELD_ID_TIMESTAMP,
-
+	MU_MSG_FIELD_ID_REFS,
+	
 	MU_MSG_FIELD_ID_NUM,
 
 	/* fake fields */

src/mu-msg-priv.h

@@ -43,6 +43,8 @@ enum _StringFields {
 	MDIR_FIELD,        /* the maildir */
 	
 	FLAGS_FIELD_STR,   /* message flags */
+
+	REFS_FIELD,        /* msg references, as a comma-sep'd string */
 	
 	FIELD_NUM
 };
@@ -59,6 +61,8 @@ struct _MuMsg {
 	size_t		_size;
 	time_t		_timestamp;	
 	MuMsgPrio       _prio;
+
+	GSList          *_refs; /* msgids of message we refer to */
 };
 
 G_END_DECLS

src/mu-msg.c

@@ -80,6 +80,9 @@ mu_msg_destroy (MuMsg *msg)
 		
 	for (i = 0; i != FIELD_NUM; ++i)
 		g_free (msg->_fields[i]);
+
+	g_slist_foreach (msg->_refs, (GFunc)g_free, NULL);
+	g_slist_free (msg->_refs);
 	
 	g_slice_free (MuMsg, msg);
 }
@@ -214,7 +217,8 @@ mu_msg_new (const char* filepath, const gchar* mdir, GError **err)
 	msg	       = g_slice_new0 (MuMsg);	
 	msg->_prio     = MU_MSG_PRIO_NONE;
 	msg->_refcount = 1;
-
+	msg->_refs     = NULL;
+	
 	if (!init_file_metadata(msg, filepath, mdir, err)) {
 		mu_msg_unref (msg);
 		return NULL;
@@ -814,6 +818,92 @@ mu_msg_get_summary (MuMsg *msg, size_t max_lines)
 }
 
 
+static GSList*
+get_msgids_from_header (MuMsg *msg, const char* header)
+{
+	GSList *msgids;
+	const char *str;
+
+	msgids = NULL;
+	str = g_mime_object_get_header (GMIME_OBJECT(msg->_mime_msg),
+					header);
+	
+	/* get stuff from the 'references' header */
+	if (str) {
+		const GMimeReferences *cur;
+		GMimeReferences *mime_refs;
+		mime_refs = g_mime_references_decode (str);
+		for (cur = mime_refs; cur; cur = g_mime_references_get_next(cur)) {
+			const char* msgid;
+			msgid = g_mime_references_get_message_id (cur);
+			if (msgid)
+				msgids = g_slist_prepend (msgids, g_strdup (msgid));
+		}
+		g_mime_references_free (mime_refs);
+	}
+
+	return g_slist_reverse (msgids);
+}
+
+const char*
+mu_msg_get_references_str (MuMsg *msg)
+{
+	const GSList *refs;
+	gchar *refsstr;
+
+	g_return_val_if_fail (msg, NULL);
+	
+	if (msg->_fields[REFS_FIELD])
+		return msg->_fields[REFS_FIELD];
+
+	refsstr = NULL;
+	refs = mu_msg_get_references (msg);
+	if (refs) {
+		const GSList *cur;
+		for (cur = refs; cur; cur = g_slist_next(cur)) {
+			char *tmp;
+			tmp = g_strdup_printf ("%s%s%s",
+					       refsstr ? refsstr : "",
+					       refsstr ? "," : "",
+					       g_strdup((gchar*)cur->data));
+			g_free (refsstr);
+			refsstr = tmp;
+		}
+	}			
+	
+	return msg->_fields[REFS_FIELD] = refsstr;
+}
+
+
+const GSList*
+mu_msg_get_references (MuMsg *msg)
+{
+	GSList *refs, *inreply;
+	
+	g_return_val_if_fail (msg, NULL);
+
+	if (msg->_refs)
+		return msg->_refs;
+
+	refs = get_msgids_from_header (msg, "References");
+	
+	/* now, add in-reply-to:, we only take the first one if there
+	 * are more */
+	inreply = get_msgids_from_header (msg, "In-reply-to");
+	if (inreply) {
+		refs = g_slist_prepend (refs, g_strdup ((gchar*)inreply->data));
+		g_slist_foreach (inreply, (GFunc)g_free, NULL);
+		g_slist_free (inreply);
+	}
+				 
+	/* put in proper order */
+	msg->_refs = g_slist_reverse (refs);
+
+	return msg->_refs;
+}
+
+
+
 const char*
 mu_msg_get_field_string (MuMsg *msg, MuMsgFieldId mfid)
 {
@@ -829,6 +919,7 @@ mu_msg_get_field_string (MuMsg *msg, MuMsgFieldId mfid)
 	case MU_MSG_FIELD_ID_TO:         return mu_msg_get_to (msg);
 	case MU_MSG_FIELD_ID_MSGID:      return mu_msg_get_msgid (msg);
 	case MU_MSG_FIELD_ID_MAILDIR:    return mu_msg_get_maildir (msg);
+	case MU_MSG_FIELD_ID_REFS:       return mu_msg_get_references_str (msg);
 	default:
 		g_return_val_if_reached (NULL);
 	}

src/mu-msg.h

@@ -292,6 +292,28 @@ MuMsgPrio   mu_msg_get_prio        (MuMsg *msg);
 time_t          mu_msg_get_timestamp       (MuMsg *msg);
 
 
+/** 
+ * get a list of message ids this message refers to -- this is based
+ * on the References: and In-reply-to: headers.
+ * 
+ * @param msg a valid MuMsg instance
+ * 
+ * @return a list of message id, with the most immediate parent as the
+ * last element. Don't modify/free this list.
+ */
+const GSList *mu_msg_get_references (MuMsg *msg);
+
+
+/** 
+ * get the list of references as a comma-separated string
+ * 
+ * @param msg a valid MuMsg
+ * 
+ * @return a comma-separated string with the references or NULL if
+ * there are none. Don't modify/free
+ */
+const char* mu_msg_get_references_str (MuMsg *msg);
+
 G_END_DECLS
 
 #endif /*__MU_MSG_H__*/