Bug#814959: Keyboard mapping broken with Qt5 apps in TightVNC, possibly due to missing XKEYBOARD extension

[Linus Lüssing]

I stumbled over this issue with various Qt5 applications on Debian
Sid, too, and had initially reported my issue here:

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=818232

Switching the VNC viewer does not seem to help, I tried
xtightvncviewer and krdc.

Not only the TightVNC server, but also the RealVNC one
(vnc4server package) seem to be affected. TigerVNC on the other
hand works like a charm (which is my current workaround for this
issue for now).

Noticeably, on TightVNC and RealVNC, I get this error message,
while on TigerVNC I don't:

"Qt: XKEYBOARD extension not present on the X server."

So looks like James initial investigations lead to the right
direction.

Unfortunately, this report on the Qt bugtracker indicates that it
was closed and deemed "out of scope" and that VNC servers should
implement this XKEYBOARD extension :-( :

https://bugreports.qt.io/browse/QTBUG-44938

This ticket also has some nice explanations why Qt5 has this issue
and Qt4 doesn't (e.g. the preference of libxkbcommon over xlib in
Qt5).

Regards, Linus

[Lisandro Damián Nicanor Pérez Meyer]

forcemerge 814959 818232
forwarded 814959 https://bugreports.qt.io/browse/QTBUG-44938
tag 814959 wontfix
thanks

On jueves, 20 de octubre de 2016 1:59:01 A. M. ART Linus Lüssing wrote:
[snip]

> Noticeably, on TightVNC and RealVNC, I get this error message,
> while on TigerVNC I don't:
>
> "Qt: XKEYBOARD extension not present on the X server."
>
> So looks like James initial investigations lead to the right
> direction.
>
> Unfortunately, this report on the Qt bugtracker indicates that it
> was closed and deemed "out of scope" and that VNC servers should
> implement this XKEYBOARD extension :-( :
>
> https://bugreports.qt.io/browse/QTBUG-44938
>
> This ticket also has some nice explanations why Qt5 has this issue
> and Qt4 doesn't (e.g. the preference of libxkbcommon over xlib in
> Qt5).

So I'm afraid this is not a Qt5 bug, but lack of proper support for XKEYBOARD
(and thus Qt5 apps) in VNC servers/clients.

I'm marking this as wontfix because it will never get "fixed" from the Qt
side. I suggest you to open the proper bugs to your VNC servers/clients.

Kinds regards, Lisandro.

--
Lo que me sorprende de las mujeres es que se arrancan los pelos desde
la raíz con cera caliente y aún así le temen a las arañas.
Jerry Seinfeld

lis: comentario sobre tu frase....
yo soy mujer, yo me arranco los pelos y VOS le tenes miedo a las arañas....
María Luján Pérez Meyer (mi hermana)

Lisandro Damián Nicanor Pérez Meyer
http://perezmeyer.com.ar/
http://perezmeyer.blogspot.com/

[Maximiliano Curia]

¡Hola!

El 2016-10-21 a las 08:43 -0300, Lisandro Damián Nicanor Pérez Meyer escribió:
> So I'm afraid this is not a Qt5 bug, but lack of proper support for XKEYBOARD
> (and thus Qt5 apps) in VNC servers/clients.

Aparentely turbovnc [1], (which started as a tightvnc fork) has added the
missing RANDR and XKEYBOARD extensions.

Disclaimer: this is not packaged, I haven't tested it, nor I've checked it's
openness. But if anyone has the time to work on this, please consider
retitling #700517.

[1]: https://sourceforge.net/projects/turbovnc/

Happy hacking,
--
"There are only two things wrong with C++: The initial concept and the
implementation."
-- Bertrand Meyer
Saludos /\/\ /\ >< `/