- (nconc params-list
- (gnus-topic-hierarchical-parameters
- ;; First we try to go to the group within the group
- ;; buffer and find the topic for the group that way.
- ;; This hopefully copes well with groups that are in
- ;; more than one topic. Failing that (i.e. when the
- ;; group isn't visible in the group buffer) we find a
- ;; topic for the group via gnus-group-topic.
- (or (and (gnus-group-goto-group group)
- (gnus-current-topic))
- (gnus-group-topic group)))))))
-
-(defun gnus-topic-hierarchical-parameters (topic)
- "Return a topic list computed for TOPIC."
- (let ((params-list (nreverse (mapcar 'gnus-topic-parameters
- (gnus-current-topics topic))))
+ (gnus-topic-hierarchical-parameters
+ ;; First we try to go to the group within the group buffer and find the
+ ;; topic for the group that way. This hopefully copes well with groups
+ ;; that are in more than one topic. Failing that (i.e. when the group
+ ;; isn't visible in the group buffer) we find a topic for the group via
+ ;; gnus-group-topic.
+ (or (and (gnus-group-goto-group group)
+ (gnus-current-topic))
+ (gnus-group-topic group))
+ params-list))))
+
+(defun gnus-topic-hierarchical-parameters (topic &optional group-params-list)
+ "Compute the topic parameters for TOPIC.
+Possibly inherit parameters from topics above TOPIC.
+If optional argument GROUP-PARAMS-LIST is non-nil, use it as the basis for
+inheritance."
+ (let ((params-list
+ ;; We probably have lots of nil elements here, so we remove them.
+ ;; Probably faster than doing this "properly".
+ (delq nil (cons group-params-list
+ (mapcar 'gnus-topic-parameters
+ (gnus-current-topics topic)))))