Re: Log out hanging after X-forwarded emacsclient

[Thomas Fitzsimmons <fitzsim@fitzsim.org>]

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Hi Adam,

"Adam Sjøgren <asjo@koldfront.dk>" writes:

> Inspired by the mention of the old GTK+-bug, I did a build of emacs like
> this:
>
>   ./configure --without-pop --with-cairo --without-dbus --with-x-toolkit=lucid && make bootstrap
>
> And then I started Emacs on the machine:
>
>   machine1:~$ /usr/src/emacs/src/emacs -Q --eval '(server-start)'
>
> On another machine, I ssh'ed to the first machine, with X-forwarding
> turned on, and started emacsclient:
>
>   machine2:~$ ssh -X machine1
>   machine1:~$ /usr/src/emacs/lib-src/emacsclient --create-frame /tmp/test.txt
>   Waiting for Emacs...
>
> And got an X frame displayed on the screen of machine2, as expected.
>
> When I then end emacsclient with C-x # I'm back at the prompt. If I run
> "exit", the prompt is hanging, where I would expect to be logged out of
> machine1 and returned to machine2. Only after I press control-c do I get
> the prompt back:
>
>   machine1:~$ exit
>   ^C
>   machine2:~$ 
>
> (When I press control-c, the message "Connection lost to X server
> 'localhost:10.0'" is displayed in the mini-buffer in the Emacs frame on
> machine1.)
>
> I thought this "hanging" was related to the display closing GTK+-bug,
> but this is with lucid. At one point, I think, I read that it was a
> dbus-related thing, but I also turned off dbus.
>
> How do I avoid this hanging/having to press control-c?

This bug is still present on the master branch.  The attached patch
works for me but it may be subject to race conditions, so I will
continue testing it.  In the meantime, I figured I would reply to this
old thread in case others are interested in trying it.

Thomas


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From 21640257edc72e0c11127db60a6cfa9e92005309 Mon Sep 17 00:00:00 2001
From: Thomas Fitzsimmons <fitzsim@fitzsim.org>
Date: Tue, 9 Apr 2024 01:00:14 -0400
Subject: [PATCH] Close X connection when emacsclient disconnects

This fixes an issue reported on the mailing list:
https://lists.gnu.org/archive/html/emacs-devel/2020-04/msg00950.html

* lisp/server.el (server-handle-delete-frame): If the frame is an
X frame and DISPLAY is set, close the X connection to the display.
---
 lisp/server.el | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lisp/server.el b/lisp/server.el
index b65053267a6..fb236493eae 100644
--- a/lisp/server.el
+++ b/lisp/server.el
@@ -509,6 +509,9 @@ server-handle-delete-frame
                             (eq proc (frame-parameter f 'client))))
                      (frame-list))))
       (server-log (format "server-handle-delete-frame, frame %s" frame) proc)
+      (let ((display (frame-parameter frame 'display)))
+        (when (and display (eq (framep frame) 'x))
+          (run-at-time nil nil (lambda () (x-close-connection display)))))
       (server-delete-client proc 'noframe)))) ; Let delete-frame delete the frame later.
 
 (defun server-handle-suspend-tty (terminal)
-- 
2.39.2