Re: `C-h f' doesn't show file where function comes from

[Katsumi Yamaoka]

>>>>> martin rudalics wrote:

> It _may_ relate to where you install Emacs.

I found out the cause of the problem.  It relates to whether
Emacs is installed or not.  That `Emacs is *not* installed' means
that a user built Emacs in the source tree and uses it there.
In that case all the .el files are not gzipped.

> The behavior you observe might be related to my recent changes.  Could
> you please try to edebug the function `find-lisp-object-file-name' in
> help-fns.el and find out why it fails to return an absolute filename for
> your settings.

With Emacs that is started with `emacs -Q -l wid-edit', the form

(find-lisp-object-file-name 'widget-button-press
                            (symbol-function 'widget-button-press))

returns nil, even though the result of the form
(symbol-function 'widget-button-press) contains the real .elc file
name:

#[(pos &optional event)
 ("/usr/local/share/emacs/23.0.60/lisp/wid-edit.elc" . 29635)
 nil 4
 ("/usr/local/share/emacs/23.0.60/lisp/wid-edit.elc" . 29551) "@d"]

In my case the source file is:

/usr/local/share/emacs/23.0.60/lisp/wid-edit.el.gz

Gzipping .el files is done by default when installing Emacs.
However, `find-lisp-object-file-name' looks for only wid-edit.el.
Here is a patch:

--8<---------------cut here---------------start------------->8---
--- help-fns.el~        2008-09-01 21:41:33 +0000
+++ help-fns.el 2008-09-08 00:01:27 +0000
@@ -295,7 +295,9 @@
        ;; When the Elisp source file can be found in the install
        ;; directory return the name of that file - `file-name' should
        ;; have become an absolute file name ny now.
-       (and (file-readable-p lib-name) lib-name)))
+       (or (and (file-readable-p lib-name) lib-name)
+           (and (file-readable-p (concat lib-name ".gz"))
+                (concat lib-name ".gz")))))
      ((let* ((lib-name (file-name-nondirectory file-name))
             ;; The next form is from `describe-simplify-lib-file-name'.
             (file-name
--8<---------------cut here---------------end--------------->8---

With this patch `C-h f widget-button-press RET' shows the file
name properly as follows:

--8<---------------cut here---------------start------------->8---
widget-button-press is an interactive compiled Lisp function in
`/local/share/emacs/23.0.60/lisp/wid-edit.el.gz'.


(widget-button-press pos &optional event)

Invoke button at pos.

[back]
--8<---------------cut here---------------end--------------->8---

The newlines under the file name seem to be too many, though.

Regards,