eldoc: modify `eldoc-documentation-function' using `add-function'

[gnu-emacs] / lisp / progmodes / elisp-mode.el

diff --git a/lisp/progmodes/elisp-mode.el b/lisp/progmodes/elisp-mode.el
index 4de40eff538cfcb03cd8158a86e3901c6d86a746..b2c5fbfe60ee3f0fbf038411dbbd11ad49db084c 100644 (file)
--- a/lisp/progmodes/elisp-mode.el
+++ b/lisp/progmodes/elisp-mode.el
@@ -231,8 +231,8 @@ Blank lines separate paragraphs.  Semicolons start comments.
   (defvar xref-identifier-completion-table-function)
   (lisp-mode-variables nil nil 'elisp)
   (setq imenu-case-fold-search nil)
-  (setq-local eldoc-documentation-function
-              #'elisp-eldoc-documentation-function)
+  (add-function :before-until (local 'eldoc-documentation-function)
+                #'elisp-eldoc-documentation-function)
   (setq-local xref-find-function #'elisp-xref-find)
   (setq-local xref-identifier-completion-table-function
               #'elisp--xref-identifier-completion-table)