Qt/gtk style difference with local vs. ssh connection

[John W. Eaton]

When I start the Octave GUI I get something that looks like the first
attached screenshot.  I'm using gnome on a Debian system and this is
the theme I expect.  If I first ssh -X localhost and then start
Octave, I get the window theme shown in the second attached
screenshot.  I don't understand the difference, or how to avoid it.

Searching the web tells me that I should ensure that the configuration
files are installed on both systems.  But In both cases, I'm logged in
to the same account on the same system, so exactly the same set of
configuration files are present in both cases.  And if I use strace to
watch what files are opened, I see that the Octave process running
over the ssh connection is not even attempting to open any gtk
configuration files.

Hmm.

OK, I compared the environments and the ssh connection did not have
DESKTOP_ENVIRONMENT=gnome.  If I export that setting, then I get
something that looks like the third attached screenshot.  At least
that is using the theme I expect, but the layout is not identical to
what I see when I run Octave locally (there is extra space around the
text box that displays the warning message).

Does anyone have a clue about what could cause this difference in the
layout?

Could someone check whether there is a similar problem for KDE users?

I'm not sure whether Octave itself can do anything about this problem,
but we could at least document it.

jwe

local.png
Description: PNG image

ssh-x.png
Description: PNG image

ssh-x-desktop-session-exported.png
Description: PNG image