; Warn of while/dolist pitfall in gnus-sum.el

Suggested by Andy Moreton in the following thread:
https://lists.gnu.org/archive/html/emacs-devel/2019-04/msg00294.html
* lisp/gnus/gnus-sum.el (gnus-summary-move-article): Add comment
warning of common while/dolist pitfall. (bug#33653#134)

diff --git a/lisp/gnus/gnus-sum.el b/lisp/gnus/gnus-sum.el
index 8959a2b3d0a65c47e3455b2ab9d17642c9dea54b..b8aa302f11a1a4c37cffe93be3c3aa6e2a771d6d 100644 (file)
--- a/lisp/gnus/gnus-sum.el
+++ b/lisp/gnus/gnus-sum.el
@@ -10088,6 +10088,7 @@ ACTION can be either `move' (the default), `crosspost' or `copy'."
                  (or (car select-method)
                      (gnus-group-decoded-name to-newsgroup))
                  articles)
+    ;; This `while' is not equivalent to a `dolist' (bug#33653#134).
     (while articles
       (setq article (pop articles))
       ;; Set any marks that may have changed in the summary buffer.