bug#56459: 29.0.50; Edebug disables Eldoc

[Dmitry Gutov]

On 01/03/2023 18:57, Eli Zaretskii wrote:
> > Date: Wed, 1 Mar 2023 18:06:56 +0200
> > Cc:max.brieiev@gmail.com,larsi@gnus.org,56459@debbugs.gnu.org,
> >   friedman@splode.com
> > From: Dmitry Gutov<dgutov@yandex.ru>
> >
> > On 01/03/2023 17:49, Eli Zaretskii wrote:
> > > > Cc:max.brieiev@gmail.com,larsi@gnus.org,56459@debbugs.gnu.org,
> > > >    friedman@splode.com
> > > > Date: Wed, 01 Mar 2023 17:42:07 +0200
> > > > From: Eli Zaretskii<eliz@gnu.org>
> > > >
> > > > So I've now reverted that change, and I'm reopening the bug.  It will
> > > > have to be fixed in some other way.
> > > One possibility would be to show the ElDoc info on the mode line when
> > > Edebug is active.  But the difficulty with that is to figure out how
> > > to revert the mode line to the original shape when Edebug finishes.
> > > We currently show the info on the mdoe line when the current buffer is
> > > a minibuffer, and remove the info in minibuffer-exit-hook, but how to
> > > do that in the Edebug case?
> > edebug-mode-hook?
> That's a starting point, but I don't think it's enough, because you
> could switch to another buffer without exiting Edebug.  I tried
> something like that and it didn't work well enough.  But maybe my
> testing was incorrect, so if you are confident that this fixes the
> problem, feel free to install (perhaps on master, though).

We could try to use more hooks, or give up and use post-command-hook.

Also switched to looking up edebug-mode instead of edebug-active because 
the latter is a global value.

diff --git a/lisp/emacs-lisp/eldoc.el b/lisp/emacs-lisp/eldoc.el
index 3f5cf0ad0dc..493ec18446f 100644
--- a/lisp/emacs-lisp/eldoc.el
+++ b/lisp/emacs-lisp/eldoc.el
@@ -296,13 +296,10 @@ eldoc-minibuffer-message
 This function displays the message produced by formatting ARGS
 with FORMAT-STRING on the mode line when the current buffer is a 
minibuffer.
 Otherwise, it displays the message like `message' would."
-  (if (minibufferp)
+  (defvar edebug-mode)
+  (if (or edebug-mode (minibufferp))
       (progn
-       (add-hook 'minibuffer-exit-hook
-                 (lambda () (setq eldoc-mode-line-string nil
-                             ;; https://debbugs.gnu.org/16920
-                             eldoc-last-message nil))
-                 nil t)
+        (add-hook 'post-command-hook #'eldoc-minibuffer--cleanup)
        (with-current-buffer
            (window-buffer
             (or (window-in-direction 'above (minibuffer-window))
@@ -321,6 +318,14 @@ eldoc-minibuffer-message
           (force-mode-line-update)))
     (apply #'message format-string args)))

+(defun eldoc-minibuffer--cleanup ()
+  (defvar edebug-mode)
+  (unless (or edebug-mode (minibufferp))
+    (setq eldoc-mode-line-string nil
+          ;; https://debbugs.gnu.org/16920
+          eldoc-last-message nil)
+    (remove-hook 'post-command-hook #'eldoc-minibuffer--cleanup)))
+
 (make-obsolete
  'eldoc-message "use `eldoc-documentation-functions' instead." 
"eldoc-1.1.0")
 (defun eldoc-message (&optional string) (eldoc--message string))