From: Eli Zaretskii <eliz@gnu.org>
Date: Sat, 8 Jul 2017 08:08:55 +0000 (+0300)
Subject: Commentary enhancement in frame.el
X-Git-Tag: emacs-26.0.90~518^2~155
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=6e2a2b334d6ab58722ddd0eda19413c115573980;p=emacs.git

Commentary enhancement in frame.el

* lisp/frame.el: Explain how to test whether a variable needs to
be added to the list of those which are watched for buffer
redisplay.
---

diff --git a/lisp/frame.el b/lisp/frame.el
index c629a9497c0..0e9f38589f9 100644
--- a/lisp/frame.el
+++ b/lisp/frame.el
@@ -2458,7 +2458,13 @@ See also `toggle-frame-maximized'."
 (make-obsolete-variable
  'window-system-version "it does not give useful information." "24.3")
 
-;; Variables which should trigger redisplay of the current buffer.
+;; Variables whose change of value should trigger redisplay of the
+;; current buffer.
+;; To test whether a given variable needs to be added to this list,
+;; write a simple interactive function that changes the variable's
+;; value and bind that function to a simple key, like F5.  If typing
+;; F5 then produces the correct effect, the variable doesn't need
+;; to be in this list; otherwise, it does.
 (mapc (lambda (var)
         (add-variable-watcher var (symbol-function 'set-buffer-redisplay)))
       '(line-spacing