bug#6192: 24.0.50; eldoc-mode: unexpected recentering

[Stephen Berman]

On Sun, 16 May 2010 14:35:48 +0200 martin rudalics <rudalics@gmx.at> wrote:

>> It's not that the bug is no longer reliably reproducible; rather, you do
>> confirm my observation that the resizing happens iff eldoc-mode is
>> enabled in the user init file.
>
> No, I can't confirm that: At the time I observed the problem for the
> first time, I always only tried it by enabling eldoc-mode in a hook.
> Currently, I simply can't reproduce it neither by running eldoc-mode in
> a hook nor by enabling it manually.

I still not sure I understand.  When you wrote:

   > I have tried the trunk with -Q now and can't trigger the resizing any
   > more, neither with a hook nor when setting it manually.

I took you to mean you started with -Q, evalled (add-hook
'emacs-lisp-mode-hook 'turn-on-eldoc-mode), visited an elisp file and
then did not observe the echo area resizing (and consequent
recentering).  When I do that I not see resizing; I only (and always)
observe the resizing when (add-hook 'emacs-lisp-mode-hook
'turn-on-eldoc-mode) is in .emacs and Emacs starts with this.  Are you
now saying you don't (now) see resizing in the latter case?

>> So what difference between running a
>> hook there and running it later could lead to the bug?
>
> Good question.  Especially because the hook should be the last thing you
> run when activating emacs-lisp-mode.  Does anything change when you
> disable font-locking?

No, the Eldoc message is shown with faces and the echo area is resized
(because the argument face is bold).  Eldoc mode sets the faces via
propertize, which evidently is not affected by font-locking.

Steve Berman