Refactor Gnus group name extraction in group completing read

* lisp/gnus/gnus-group.el (gnus-group-completing-read): Only do the
  unibyte check once; make sure it applies to hash table keys as
  well.

1 files changed, 17 insertions, 24 deletions

diff --git a/lisp/gnus/gnus-group.el b/lisp/gnus/gnus-group.el
index bd24c3f8dab..0be38541745 100644
--- a/lisp/gnus/gnus-group.el
+++ b/lisp/gnus/gnus-group.el
@@ -2173,30 +2173,23 @@ Non-ASCII group names are allowed.  The arguments are the same as
 they are omitted.  Can handle COLLECTION as a list, hash table,
 or vector."
   (or collection (setq collection gnus-active-hashtb))
-  (let (choices group)
-    (cond ((listp collection)
-           (if (symbolp (car collection))
-               (dolist (symbol collection)
-                 (setq group (symbol-name symbol))
-                 (push (if (string-match "[^\000-\177]" group)
-                           (gnus-group-decoded-name group)
-                         group)
-                       choices))
-             (setq choices collection)))
-          ((vectorp collection)
-           (mapatoms (lambda (symbol)
-                       (setq group (symbol-name symbol))
-                       (push (if (string-match "[^\000-\177]" group)
-                                 (gnus-group-decoded-name group)
-                               group)
-                             choices))
-                     collection))
-          ((hash-table-p collection)
-           (setq choices (hash-table-keys collection))))
-    (setq group (gnus-completing-read (or prompt "Group") (reverse choices)
-                                      require-match initial-input
-                                      (or hist 'gnus-group-history)
-                                      def))
+  (let* ((choices
+          (mapcar
+           (lambda (g)
+             (if (string-match "[^\000-\177]" g)
+                 (gnus-group-decoded-name g)
+               g))
+           (cond ((listp collection)
+                  collection)
+                 ((vectorp collection)
+                  (mapatoms #'symbol-name collection))
+                 ((hash-table-p collection)
+                  (hash-table-keys collection)))))
+         (group
+          (gnus-completing-read (or prompt "Group") (reverse choices)
+                                require-match initial-input
+                                (or hist 'gnus-group-history)
+                                def)))
     (unless (cond ((and (listp collection)
                         (symbolp (car collection)))
                    (member group (mapcar 'symbol-name collection)))