* lisp/emacs-lisp/eldoc.el (eldoc-documentation-function): Change default.

[gnu-emacs] / lisp / emacs-lisp / eldoc.el

diff --git a/lisp/emacs-lisp/eldoc.el b/lisp/emacs-lisp/eldoc.el
index 6dddf5b9a40a97888c62b14c63d364b9db22ac84..2ee3d23714cb949ff40d84d464b2485227f834be 100644 (file)
--- a/lisp/emacs-lisp/eldoc.el
+++ b/lisp/emacs-lisp/eldoc.el
@@ -79,8 +79,8 @@ This has two preferred values: `upcase' or `downcase'.
 Actually, any name of a function which takes a string as an argument and
 returns another string is acceptable.
 
-Note that if `eldoc-documentation-function' is non-nil, this variable
-has no effect, unless the function handles it explicitly."
+Note that this variable has no effect, unless
+`eldoc-documentation-function' handles it explicitly."
   :type '(radio (function-item upcase)
                (function-item downcase)
                 function)
@@ -102,8 +102,8 @@ If value is nil, messages are always truncated to fit in a single line of
 display in the echo area.  Function or variable symbol name may be
 truncated to make more of the arglist or documentation string visible.
 
-Note that if `eldoc-documentation-function' is non-nil, this variable
-has no effect, unless the function handles it explicitly."
+Note that this variable has no effect, unless
+`eldoc-documentation-function' handles it explicitly."
   :type '(radio (const :tag "Always" t)
                 (const :tag "Never" nil)
                 (const :tag "Yes, but truncate symbol names if it will\
@@ -186,7 +186,7 @@ expression point is on."
   :group 'eldoc :lighter eldoc-minor-mode-string
   (setq eldoc-last-message nil)
   (cond
-   ((not eldoc-documentation-function)
+   ((memq eldoc-documentation-function '(nil ignore))
     (message "There is no ElDoc support in this buffer")
     (setq eldoc-mode nil))
    (eldoc-mode
@@ -225,7 +225,9 @@ expression point is on."
             eldoc-idle-delay t
             (lambda ()
                (when (or eldoc-mode
-                         (and global-eldoc-mode eldoc-documentation-function))
+                         (and global-eldoc-mode
+                              (not (memq eldoc-documentation-function
+                                         '(nil ignore)))))
                  (eldoc-print-current-symbol-info))))))
 
   ;; If user has changed the idle delay, update the timer.
@@ -321,7 +323,7 @@ Otherwise work like `message'."
 
 \f
 ;;;###autoload
-(defvar eldoc-documentation-function nil
+(defvar eldoc-documentation-function #'ignore
   "Function to call to return doc string.
 The function of no args should return a one-line string for displaying
 doc about a function etc. appropriate to the context around point.