bug#31169: 26.1; Emacs 26.1 RC1 (gtk) display issues over SSH/X11 with x

> Is this all you see in the Emacs frame? It looks like a part of a
> frame , did you clip the image, perhaps? If so, please show all of the frame.

That was all the frame. Including new attachment [emacs26_gtk3.png] for clarity. (show a little of background and putty window). I tried resizing window and same result.

> To make sure this is related to GTK, could you try building with a
> different toolkit, just to see if that build starts as expected?

Attached with "motif" x-toolkit screenshot. [emacs26_motif.png].

Appears OK, but I can't ./configure --with-xwidgets

> Does it eat CPU cycles?

No - just looked a 'top' output.

> Can you exit it with "C-x C-c" or do you have to kill it by a
signal?

C-x C-x works.

> Can you attach GDB to it (on the GNU/Linux side) and show a C
backtrace?

I attempted to do GDB backtrace even though its starting to get beyond my comfort zone.
Results attached for CentOS7 and Leap 42.3. Likely I didn't do this correctly to be useful - please advise.

Thanks!

On Mon, Apr 16, 2018 at 1:40 PM, Eli Zaretskii <eliz@gnu.org> wrote:

> From: charlie hemlock <charliehemlock@gmail.com>
> Date: Sun, 15 Apr 2018 20:09:42 -0400
>
> 1. Build emacs 26 RC1 with --with-x-toolkit=gtk3
> a. confirm builds and runs ok when run local
> 2. Login to windows box, launch ssh -X putty session to linux host with
> emacs 26 installed. (windows xserver: vcxsrv or xming)
> 3. emacs -Q
> 4. Emacs does not display correctly. Missing minibuffer, & can't type in buffer. Compare to attached
> screenshot.

Is this all you see in the Emacs frame? It looks like a part of a
frame, did you clip the image, perhaps? If so, please show all of the
frame.

> I can compile Emacs 26.1 RC1 ok, and use it locally on the host fine.
>
> However, when attempting to ssh -X to host via PuTTY 0.70 and launch the Emacs gui (emacs -Q), emacs
> is not displaying correctly. Using Windows xserver program VcXsrv (1.19.6.3).
>
> See attached screenshot - no default welcome screen, and missing minibuffer too.

It sounds like Emacs is hung or infloops somewhere. Does it eat CPU
cycles? Can you exit it with "C-x C-c" or do you have to kill it by a
signal? Can you attach GDB to it (on the GNU/Linux side) and show a C
backtrace? Please do this several times, restarting Emacs each time,
to make sure the backtrace points to the same place.

> I suspect this issue is related to some combination of GTK and
> Xming/VcXsrv, however the behavior does change between Emacs 25.3 and 26.1 RC1, see table below:

To make sure this is related to GTK, could you try building with a
different toolkit, just to see if that build starts as expected?

> Possibly related posts:
> -
> https://emacs.stackexchange.com/questions/40990/emacs-aborted-core-dumped-centos-7-0-emacs-25-3-please-help
>
> - https://bugs.launchpad.net/elementaryos/+bug/1355274
> - https://bugzilla.gnome.org/show_bug.cgi?id=85715

These don't look related to me, because the problems they describe
existed before Emacs 25, which you say worked OK for you.

Thanks.

From:	charlie hemlock
Subject:	bug#31169: 26.1; Emacs 26.1 RC1 (gtk) display issues over SSH/X11 with xming/vcxsrv
Date:	Mon, 16 Apr 2018 19:37:44 -0400