Fix shortdoc-add-function section creation

* lisp/emacs-lisp/shortdoc.el (shortdoc-add-function): Use nconc to
actually append a new section to the list of groups while avoiding a
previous OBOE.  Push a new group to the front of shortdoc--groups
without copying it, just like define-short-documentation-group does.
(buffer): Fix copypasta in unlock-buffer example.

* test/lisp/emacs-lisp/shortdoc-tests.el (shortdoc-examples): Also
check that :no-value forms demonstrate the right function.

* doc/lispref/help.texi (Documentation Groups): Clarify that @dots
in the define-short-documentation-group arglist refer to whole
key-value pairs.  Fix typo in :eg-result-string description.

1 files changed, 3 insertions, 3 deletions

diff --git a/lisp/emacs-lisp/shortdoc.el b/lisp/emacs-lisp/shortdoc.el
index 16e83074764..4ff7cee623c 100644
--- a/lisp/emacs-lisp/shortdoc.el
+++ b/lisp/emacs-lisp/shortdoc.el
@@ -887,7 +887,7 @@ There can be any number of :example/:result elements."
   (lock-buffer
    :no-value (lock-buffer "/tmp/foo"))
   (unlock-buffer
-   :no-value (lock-buffer)))
+   :no-value (unlock-buffer)))
 
 (define-short-documentation-group overlay
   "Predicates"
@@ -1283,11 +1283,11 @@ Example:
   (let ((glist (assq group shortdoc--groups)))
     (unless glist
       (setq glist (list group))
-      (setq shortdoc--groups (append shortdoc--groups (list glist))))
+      (push glist shortdoc--groups))
     (let ((slist (member section glist)))
       (unless slist
         (setq slist (list section))
-        (setq slist (append glist slist)))
+        (nconc glist slist))
       (while (and (cdr slist)
                   (not (stringp (cadr slist))))
         (setq slist (cdr slist)))