From 14c226017b0e868cf68aef8f4d3b9a1e8cd94ab7 Mon Sep 17 00:00:00 2001 From: Mauro Aranda Date: Sat, 29 Aug 2020 13:07:32 -0300 Subject: [PATCH] Improve documentation for custom :options * doc/lispref/customize.texi (Variable Definitions): Mention that re-evaluating a defcustom form doesn't reset custom options. (Bug#30101) --- doc/lispref/customize.texi | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/doc/lispref/customize.texi b/doc/lispref/customize.texi index 2a72276bc5..fcfc0d297e 100644 --- a/doc/lispref/customize.texi +++ b/doc/lispref/customize.texi @@ -358,6 +358,10 @@ Variable Definitions @code{hook}, @code{plist} and @code{alist}. See the definition of the individual types for a description of how to use @code{:options}. +Re-evaluating a @code{defcustom} form with a different :options value +does not clear the values added by previous evaluations, or by +calls to @code{custom-add-frequent-value} (see below). + @item :set @var{setfunction} @kindex set@r{, @code{defcustom} keyword} Specify @var{setfunction} as the way to change the value of this @@ -485,6 +489,10 @@ Variable Definitions The precise effect of adding a value depends on the customization type of @var{symbol}. + +Since evaluating a @code{defcustom} form does not clear values added +previously, Lisp programs can use this function to add values for user +options not yet defined. @end defun Internally, @code{defcustom} uses the symbol property -- 2.28.0