bug#30994: 27.0.50; Cursor doesn't blink (X window system)

bug#30994: 27.0.50; Cursor doesn't blink (X window system)

[Michael Heerdegen]

[-- Attachment #1: Type: text/plain, Size: 464 bytes --]


Hello,

I start emacs -Q (under openbox in X on Debian if it matters), and I get
an Emacs where the cursor doesn't blink.  Thankfully only on master but
not with an emacs-26 build.

The problem is simply that `blink-cursor-mode' is not turned on when
starting, but I can successfully enable it.

The reason is that at the moment the :init-value expression of
`blink-cursor-mode' is evaluated, `window-system' is bound to nil,
i.e. when installing the following:


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: 0001-WIP-test-no-blinking-cursor.patch --]
[-- Type: text/x-diff, Size: 1079 bytes --]

From befd2667396125748d6e9e0e15c5fc38f7846082 Mon Sep 17 00:00:00 2001
From: Michael Heerdegen <michael_heerdegen@web.de>
Date: Fri, 30 Mar 2018 04:25:00 +0200
Subject: [PATCH] WIP: test no-blinking-cursor

---
 lisp/frame.el | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/lisp/frame.el b/lisp/frame.el
index fbf2f6e773..b07e2800ba 100644
--- a/lisp/frame.el
+++ b/lisp/frame.el
@@ -2357,10 +2357,12 @@ blink-cursor-mode
 
 This command is effective only on graphical frames.  On text-only
 terminals, cursor blinking is controlled by the terminal."
-  :init-value (not (or noninteractive
-		       no-blinking-cursor
-		       (eq system-type 'ms-dos)
-		       (not (memq window-system '(x w32 ns)))))
+  :init-value (progn
+                (message "window-system: %S" window-system)
+                (not (or noninteractive
+		         no-blinking-cursor
+		         (eq system-type 'ms-dos)
+                         (not (memq window-system '(x w32 ns))))))
   :initialize 'custom-initialize-delay
   :group 'cursor
   :global t
-- 
2.16.2


[-- Attachment #3: Type: text/plain, Size: 494 bytes --]


I get a *Messages* buffer like

| window-system: nil
| For information about GNU Emacs and the GNU system, type C-h C-a.

After starting up,

window-system
   ==> x

as expected.


Thanks,

Michael.


In GNU Emacs 27.0.50 (build 5, x86_64-pc-linux-gnu, GTK+ Version 3.22.29)
 of 2018-03-30 built on drachen
Repository revision: befd2667396125748d6e9e0e15c5fc38f7846082
Windowing system distributor 'The X.Org Foundation', version 11.0.11906000
System Description: Debian GNU/Linux buster/sid

bug#30994: 27.0.50; Cursor doesn't blink (X window system)

[Glenn Morris]

I guess (without testing) that this is due to 2db57579b0 moving
custom-reevaluate-setting before the window setup. (I note there's no
blinking in emacs started as --daemon in earlier versions of Emacs for
similar reasons.)

bug#30994: 27.0.50; Cursor doesn't blink (X window system)

[Eli Zaretskii]

> From: Glenn Morris <rgm@gnu.org>
> Date: Fri, 30 Mar 2018 01:05:12 -0400
> Cc: 30994@debbugs.gnu.org
> 
> I guess (without testing) that this is due to 2db57579b0 moving
> custom-reevaluate-setting before the window setup.

Can we fix that by calling custom-reevaluate-setting one more time
after the window setup?

bug#30994: 27.0.50; Cursor doesn't blink (X window system)

[Glenn Morris]

Eli Zaretskii wrote:

>> I guess (without testing) that this is due to 2db57579b0 moving
>> custom-reevaluate-setting before the window setup.
>
> Can we fix that by calling custom-reevaluate-setting one more time
> after the window setup?

I don't know. It seems ugly to call it twice, but perhaps it works.

I guess that it would clobber "early init" settings made outside the
customize mechanism, but I haven't looked at how this new init file is
supposed to work.

bug#30994: 27.0.50; Cursor doesn't blink (X window system)

[Eli Zaretskii]

> From: Glenn Morris <rgm@gnu.org>
> Cc: michael_heerdegen@web.de,  30994@debbugs.gnu.org
> Date: Fri, 30 Mar 2018 21:04:33 -0400
> 
> Eli Zaretskii wrote:
> 
> >> I guess (without testing) that this is due to 2db57579b0 moving
> >> custom-reevaluate-setting before the window setup.
> >
> > Can we fix that by calling custom-reevaluate-setting one more time
> > after the window setup?
> 
> I don't know. It seems ugly to call it twice, but perhaps it works.

We already do such things with other features.  Sometimes it's
necessary.

> I guess that it would clobber "early init" settings made outside the
> customize mechanism, but I haven't looked at how this new init file is
> supposed to work.

Another idea is to define a function that would re-evaluate only
certain specific defcustoms, then add that function to
after-init-hook.  But that is more problematic, because maintaining
the list of defcustoms which need this is a maintenance burden.

bug#30994: 27.0.50; Cursor doesn't blink (X window system)

[Eli Zaretskii]

See more discussions of this issue in this thread:

  http://lists.gnu.org/archive/html/emacs-devel/2018-06/msg00349.html

I think I fixed the original problem now.  I'm leaving the bug open
because the secondary issue of clobbering user customizations of
variables in the custom-delayed-init-variables list still needs
attention, perhaps some reasonable solution could be found.  For now,
I just added to the docs a warning against moving customizations into
the early init file that don't have to be there.

Thanks.

bug#30994: 27.0.50; Cursor doesn't blink (X window system)

[Stefan Kangas]

Eli Zaretskii <eliz@gnu.org> writes:

> See more discussions of this issue in this thread:
>
>   http://lists.gnu.org/archive/html/emacs-devel/2018-06/msg00349.html
>
> I think I fixed the original problem now.  I'm leaving the bug open
> because the secondary issue of clobbering user customizations of
> variables in the custom-delayed-init-variables list still needs
> attention, perhaps some reasonable solution could be found.  For now,
> I just added to the docs a warning against moving customizations into
> the early init file that don't have to be there.

(That was 2 years ago.)

Has the custom-delayed-init-variables problem discussed here been
solved?

Best regards,
Stefan Kangas

bug#30994: 27.0.50; Cursor doesn't blink (X window system)

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Sat, 22 Aug 2020 21:24:22 -0400
> Cc: michael_heerdegen@web.de, 30994@debbugs.gnu.org
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > See more discussions of this issue in this thread:
> >
> >   http://lists.gnu.org/archive/html/emacs-devel/2018-06/msg00349.html
> >
> > I think I fixed the original problem now.  I'm leaving the bug open
> > because the secondary issue of clobbering user customizations of
> > variables in the custom-delayed-init-variables list still needs
> > attention, perhaps some reasonable solution could be found.  For now,
> > I just added to the docs a warning against moving customizations into
> > the early init file that don't have to be there.
> 
> (That was 2 years ago.)
> 
> Has the custom-delayed-init-variables problem discussed here been
> solved?

I don't think so, but we should probably close this bug anyway, and
leave the rest for another day/bug.

Thanks.

bug#30994: 27.0.50; Cursor doesn't blink (X window system)

[Stefan Kangas]

Eli Zaretskii <eliz@gnu.org> writes:

> I don't think so, but we should probably close this bug anyway, and
> leave the rest for another day/bug.

Thanks, I'm therefore closing this bug report.