Greetings.
On Tue, 8 Nov 2016 08:04:20 +0100, Ulrich Sibiller <uli42@gmx.de> wrote:
For example, if I launch the Xfce Terminal, I see the usual "File", "Edit", "View", "Terminal", "Tabs", and "Help" labels in the pull-down menu bar. If I click on these, they become underlined as though they are active, but the corresponding pull-down menu doesn't (usually) appear. Instead, a single pixel in the upper left corner of my desktop turns white. The only exception is when I click on "Help" -- the first time I do this, I do get a pull-down menu, but it's attached to the upper left corner of my desktop, not to the "Help" label in the Terminal window. The menu is very small, though, and I need to scroll through it to see all the entries. The second or subquent times I try to view the "Help" menu, I just get a single pixel.
This sounds like a window manager problem.
I'm not so sure. I haven't upgraded the window manager since July 2015, and I'm sure that pull-down menus were working fine until relatively recently (i.e., in the last month or two). Also, the problem happens only when using x2go, not when running applications locally or over ssh. I'm using KWin 4.11.20 on the client.
Similar behaviour is observed in most other GTK+2 and GTK+3 applications, such as the GNOME Terminal and the GNOME Character Map. The problem is reproducible when launhcing LibreOffice with SAL_USE_VCLPLUGIN=gtk2 or SAL_USE_VCLPLUGIN=gtk3, but not with SAL_USE_VCLPLUGIN=kde4 or SAL_USE_VCLPLUGIN=gen. Some (but not all) of the applications output error messages like this to the console when I try to activate a pull-down menu:
(gucharmap:26208): Gtk-CRITICAL **: gtk_widget_get_preferred_height_for_width: assertion 'width >= 0' failed
(gucharmap:26208): Gtk-CRITICAL **: gtk_widget_get_preferred_height_for_width: assertion 'width >= 0' failed
(gucharmap:26208): Gtk-CRITICAL **: gtk_widget_get_preferred_height_for_width: assertion 'width >= 0' failed
(gucharmap:26208): Gtk-WARNING **: Negative content width -7 (allocation 1, extents 4x4) while allocating gadget (node arrow, owner GtkMenu)
(gucharmap:26208): Gtk-WARNING **: Negative content width -7 (allocation 1, extents 4x4) while allocating gadget (node arrow, owner GtkMenu)
Googling for these messages leads to bugs regarding xwayland and HiDPI monitors, which does not fit in here (e.g.: https://bugs.documentfoundation.org/show_bug.cgi?id=99508), but they sugges using
SAL_USE_VCLPLUGIN=gtk
Does that help?
Yes, using SAL_USE_VCLPLUGIN=gtk, the pull-down menus work in LibreOffice. Of course, this is of no help for other GTK+ applications.
Anyone know what the cause might be and how I can work around it? I'm running x2goserver-4.0.1.19 on an openSUSE Tumbleweed server and x2goclient-4.0.5.0 on an openSUSE 13.2 client. The client desktop environment is KDE 5.
Have you checked if it works at all without x2go?
Yes. Pull-down menus for all applications work fine when run locally on the server (or locally on the client, for that matter). They also work fine when I run them remotely via ssh -X. They appear correctly, and no error messages are emitted to the console. It's only when running them remotely via x2go that they don't work.
Regards, Tristan
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Tristan Miller