Improve propagation of gnus/nnselect group info

* lisp/gnus/nnselect.el (nnselect-push-info): Speed up pushing the
nnselect info back to the originating groups.

1 files changed, 20 insertions, 10 deletions

diff --git a/lisp/gnus/nnselect.el b/lisp/gnus/nnselect.el
index 586dec65af8..d6289f13395 100644
--- a/lisp/gnus/nnselect.el
+++ b/lisp/gnus/nnselect.el
@@ -878,6 +878,9 @@ article came from is also searched."
               ;; When the backend can store marks we collect any
               ;; changes.  Unlike a normal group the mark lists only
               ;; include marks for articles we retrieved.
+              (when (and (gnus-check-backend-function
+                          'request-set-mark gnus-newsgroup-name)
+                         (not (gnus-article-unpropagatable-p type)))
                 (let* ((old (range-list-intersection
                              artlist
                              (alist-get type (gnus-info-marks group-info))))
@@ -889,7 +892,7 @@ article came from is also searched."
                     ;; This shouldn't happen, but is a sanity check.
                     (setq del (range-intersection
                                (gnus-active artgroup) del))
-                    (push (list del 'del (list type)) delta-marks)))
+                    (push (list del 'del (list type)) delta-marks))))
 
               ;; Marked sets are of mark-type 'tuple, 'list, or
               ;; 'range. We merge the lists with what is already in
@@ -914,12 +917,15 @@ article came from is also searched."
                     (setq list (cdr all))))
                 ;; now merge with the original list and sort just to
                 ;; make sure
-                (setq list
-                      (sort (map-merge
-                             'alist list
-                             (alist-get type (gnus-info-marks group-info)))
-                            (lambda (elt1 elt2)
-                              (< (car elt1) (car elt2))))))
+                (setq
+                 list (sort
+                       (map-merge
+                        'alist list
+                        (delq nil
+                              (mapcar
+                               (lambda (x) (unless (memq (car x) artlist) x))
+                               (alist-get type (gnus-info-marks group-info)))))
+                       'car-less-than-car)))
                (t
                 (setq list
                       (range-compress-list
@@ -963,9 +969,13 @@ article came from is also searched."
                 (cdr (assoc artgroup select-reads)))
                (sort (cdr (assoc artgroup select-unreads)) #'<))))
             (gnus-get-unread-articles-in-group
-             group-info (gnus-active artgroup) t)
-            (gnus-group-update-group artgroup t t)))))))
-
+             group-info (gnus-active artgroup) t))
+            (gnus-group-update-group
+             artgroup t
+             (equal group-info
+                    (setq group-info (copy-sequence (gnus-get-info artgroup))
+                          group-info
+                          (delq (gnus-info-params group-info) group-info)))))))))
 
 (declare-function gnus-registry-get-id-key "gnus-registry" (id key))