From a98413726f5a10676f9faf4c4013ac6eaa53b42b Mon Sep 17 00:00:00 2001
From: Stefan Monnier <monnier@iro.umontreal.ca>
Date: Tue, 7 Jun 2022 10:30:47 -0400
Subject: [PATCH] find-func.el: Fix bug#41104

* lisp/emacs-lisp/find-func.el (find-function-advised-original): Look
at the actual function definition rather than
`advice--symbol-function` which sometimes returns only the advice.

* test/lisp/emacs-lisp/find-func-tests.el
(find-func-tests--find-library-verbose): Add test.
---
 lisp/emacs-lisp/find-func.el            | 6 +++---
 test/lisp/emacs-lisp/find-func-tests.el | 7 +++++++
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/lisp/emacs-lisp/find-func.el b/lisp/emacs-lisp/find-func.el
index 96eaf1ab642..2dec51dd044 100644
--- a/lisp/emacs-lisp/find-func.el
+++ b/lisp/emacs-lisp/find-func.el
@@ -270,7 +270,7 @@ If FUNC is not a symbol, return it.  Else, if it's not advised,
 return the symbol's function definition."
   (or (and (symbolp func)
            (featurep 'nadvice)
-           (let ((ofunc (advice--symbol-function func)))
+           (let ((ofunc (symbol-function func)))
              (if (advice--p ofunc)
                  (advice--cd*r ofunc)
                ofunc)))
@@ -516,8 +516,8 @@ Return t if any PRED returns t."
 (defun find-function-library (function &optional lisp-only verbose)
   "Return the pair (ORIG-FUNCTION . LIBRARY) for FUNCTION.
 
-ORIG-FUNCTION is the original name, after removing all advice and
-resolving aliases.  LIBRARY is an absolute file name, a relative
+ORIG-FUNCTION is the original name, after resolving aliases.
+LIBRARY is an absolute file name, a relative
 file name inside the C sources directory, or a name of an
 autoloaded feature.
 
diff --git a/test/lisp/emacs-lisp/find-func-tests.el b/test/lisp/emacs-lisp/find-func-tests.el
index d29d9ff6563..420c61acb55 100644
--- a/test/lisp/emacs-lisp/find-func-tests.el
+++ b/test/lisp/emacs-lisp/find-func-tests.el
@@ -95,6 +95,13 @@ expected function symbol and function library, respectively."
   (advice-remove #'mark-sexp 'my-message))
 
 (ert-deftest find-func-tests--find-library-verbose ()
+  (unwind-protect
+      (progn
+        (advice-add 'dired :before #'ignore)
+        ;; bug#41104
+        (should (equal (find-function-library #'dired) '(dired . "dired"))))
+    (advice-remove 'dired #'ignore))
+
   (find-function-library #'join-line nil t)
   (with-current-buffer "*Messages*"
     (save-excursion
-- 
2.39.2