Make eval-defun on a pre-defined defcustom call any :set function

* lisp/emacs-lisp/lisp-mode.el (eval-defun-1): Doc fix.
Respect a defcustom's :set function, if appropriate. 
(eval-defun): Doc fix.

* doc/lispref/customize.texi (Variable Definitions): Mention eval-defun
on a defcustom calls the :set function when appropriate.

* etc/NEWS: Mention this.

Fixes: debbugs:109

2 files changed, 9 insertions, 2 deletions

diff --git a/doc/lispref/ChangeLog b/doc/lispref/ChangeLog
index a26bfdc2e4b..7238d958d8a 100644
--- a/doc/lispref/ChangeLog
+++ b/doc/lispref/ChangeLog
@@ -1,3 +1,8 @@
+2012-12-09  Glenn Morris  <rgm@gnu.org>
+
+        * customize.texi (Variable Definitions): Mention eval-defun
+        on a defcustom calls the :set function when appropriate.
+
 2012-12-06  Paul Eggert  <eggert@cs.ucla.edu>
 
         * doclicense.texi, gpl.texi: Update to latest version from FSF.
diff --git a/doc/lispref/customize.texi b/doc/lispref/customize.texi
index 1fb8bb3e71a..c8d09760b53 100644
--- a/doc/lispref/customize.texi
+++ b/doc/lispref/customize.texi
@@ -308,8 +308,10 @@ Every @code{defcustom} should specify @code{:group} at least once.
 When you evaluate a @code{defcustom} form with @kbd{C-M-x} in Emacs Lisp
 mode (@code{eval-defun}), a special feature of @code{eval-defun}
 arranges to set the variable unconditionally, without testing whether
-its value is void.  (The same feature applies to @code{defvar}.)
-@xref{Defining Variables}.
+its value is void.  (The same feature applies to @code{defvar},
+@pxref{Defining Variables}.)  Using @code{eval-defun} on a defcustom
+that is already defined calls the @code{:set} function (see below),
+if there is one.
 
 If you put a @code{defcustom} in a pre-loaded Emacs Lisp file
 (@pxref{Building Emacs}), the standard value installed at dump time