+/* Does the address in the Reply-To header of 'message' already appear
+ * in either the 'To' or 'Cc' header of the message?
+ */
+static int
+reply_to_header_is_redundant (notmuch_message_t *message)
+{
+ const char *reply_to, *to, *cc, *addr;
+ InternetAddressList *list;
+ InternetAddress *address;
+ InternetAddressMailbox *mailbox;
+
+ reply_to = notmuch_message_get_header (message, "reply-to");
+ if (reply_to == NULL || *reply_to == '\0')
+ return 0;
+
+ list = internet_address_list_parse_string (reply_to);
+
+ if (internet_address_list_length (list) != 1)
+ return 0;
+
+ address = internet_address_list_get_address (list, 0);
+ if (INTERNET_ADDRESS_IS_GROUP (address))
+ return 0;
+
+ mailbox = INTERNET_ADDRESS_MAILBOX (address);
+ addr = internet_address_mailbox_get_addr (mailbox);
+
+ to = notmuch_message_get_header (message, "to");
+ cc = notmuch_message_get_header (message, "cc");
+
+ if ((to && strstr (to, addr) != 0) ||
+ (cc && strstr (cc, addr) != 0))
+ {
+ return 1;
+ }
+
+ return 0;
+}
+
+/* Augment the recipients of 'reply' from the "Reply-to:", "From:",
+ * "To:", "Cc:", and "Bcc:" headers of 'message'.
+ *
+ * If 'reply_all' is true, use sender and all recipients, otherwise
+ * scan the headers for the first that contains something other than
+ * the user's addresses and add the recipients from this header
+ * (typically this would be reply-to-sender, but also handles reply to
+ * user's own message in a sensible way).
+ *
+ * If any of the user's addresses were found in these headers, the
+ * first of these returned, otherwise NULL is returned.
+ */
+static const char *
+add_recipients_from_message (GMimeMessage *reply,
+ notmuch_config_t *config,
+ notmuch_message_t *message,
+ notmuch_bool_t reply_all)