bug#8304: 23.2; ad-read-advised-function default to func at point

[Kevin Ryde]

When using the advice.el things interactively, eg. ad-disable-advice or
ad-activate, it'd be good if the read for the function name defaulted to
a func at point.

Currently I think it only offers the most recently defined advice, so
with

    (defadvice doctor (around no-doctoring activate)
      "Disable the doctor."
      (error "The doctor is at a medical conference in Barbados"))
    (defadvice dunnet (around no-games activate)
      "Disable games."
      (error "Shouldn't you be working?"))

An M-x ad-disable-advice with point on either "doctor" or "dunnet"
offers "dunnet", where I hoped that on "doctor" it would offer doctor.

2011-03-20  Kevin Ryde  <user42@zip.com.au>

        * emacs-lisp/advice.el (ad-read-advised-function): Use
        `function-called-at-point' as the default default, if the func at
        point has advice, and passes PREDICATE.

--- advice.el.~1.68.~   2009-10-08 11:00:28.000000000 +1100
+++ advice.el   2011-03-21 10:37:14.000000000 +1100
@@ -2200,16 +2200,29 @@
 ;; @@ Interactive input functions:
 ;; ===============================
 
+(declare-function 'function-called-at-point "help")
+
 (defun ad-read-advised-function (&optional prompt predicate default)
   "Read name of advised function with completion from the minibuffer.
 An optional PROMPT will be used to prompt for the function.  PREDICATE
-plays the same role as for `try-completion' (which see).  DEFAULT will
-be returned on empty input (defaults to the first advised function for
-which PREDICATE returns non-nil)."
+plays the same role as for `try-completion' (which see).
+
+DEFAULT is returned on empty input.  DEFAULT defaults to the
+function name at point if it's advised and passes PREDICATE,
+otherwise to the first advised function which passes PREDICATE."
   (if (null ad-advised-functions)
       (error "ad-read-advised-function: There are no advised functions"))
   (setq default
        (or default
+           ;; prefer func name at point, if it's in ad-advised-functions etc
+           (let ((function (progn
+                             (require 'help)
+                             (function-called-at-point))))
+             (and function
+                  (assoc (symbol-name function) ad-advised-functions)
+                  (or (null predicate)
+                      (funcall predicate function))
+                  function))
            (ad-do-advised-functions (function)
              (if (or (null predicate)
                      (funcall predicate function))



In GNU Emacs 23.2.1 (i486-pc-linux-gnu, GTK+ Version 2.20.0)
 of 2010-05-16 on raven, modified by Debian
configured using `configure  '--build' 'i486-linux-gnu' '--build' 
'i486-linux-gnu' '--prefix=/usr' '--sharedstatedir=/var/lib' 
'--libexecdir=/usr/lib' '--localstatedir=/var/lib' '--infodir=/usr/share/info' 
'--mandir=/usr/share/man' '--with-pop=yes' 
'--enable-locallisppath=/etc/emacs23:/etc/emacs:/usr/local/share/emacs/23.2/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.2/site-lisp:/usr/share/emacs/site-lisp:/usr/share/emacs/23.2/leim'
 '--with-x=yes' '--with-x-toolkit=gtk' '--with-toolkit-scroll-bars' 
'build_alias=i486-linux-gnu' 'CFLAGS=-DDEBIAN -g -O2' 'LDFLAGS=-g' 'CPPFLAGS=''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_AU
  value of $XMODIFIERS: nil
  locale-coding-system: iso-latin-1-unix
  default enable-multibyte-characters: t