I tracked this, I am answering myself for the record.

On my system, I had to recompile OSG.
It seems on left-shift-key release, Xorg sends a release event with a wrong
keysym (XK_ISO_Prev_Group instead of XK_Shift_L).

Same thing for right shift key. On release, the X11 keysym is
XK_ISO_Next_Group instead of XK_Shift_R.

So i  remap these in OSG through the _extendedKeymap of GraphicsWindowX11.
I add the following remappings in GraphicsWindowX11.cpp of osgViewer:

            _extendedKeymap[XK_ISO_Prev_Group] = osgGA::GUIEventAdapter::KEY_Shift_L;
            _extendedKeymap[XK_ISO_Next_Group] = osgGA::GUIEventAdapter::KEY_Shift_R;

Not sure this is the correct solution, though. It works for me.

Maybe this concerns OSG people? Xorg people?


On Tue, Jun 28, 2011 at 7:23 PM, Sylvain Mazet <sylvain.mazet@gmail.com> wrote:
Hi all,

First things first: I am a long time user of FlightGear (for play),
I just love it.

Since using FlightGear-2.0.0, I have a keyboard problem.

Keyboard responds OK, except that the shift modifier,
once activated, stays on forever.
1) I start FlightGear,
2) I press 'x', I zoom in OK,
3) I press 'shift-x', I zoom out OK,
4) I press 'x', nothing happens. The shift modifier
is still there (I activated the "dump" in keyboard.xml to see this).

My system is an up-to-date Debian Linux Squeeze. I use gnome.

I tried:
 - Simgear/FlightGear-2.0.0 bundle
 - Simgear/FlightGear git version (of yesterday: 2.3.0-something)
 - OpenSceneGraph 2.8.2, and latest 3.0.0 (I am not sure it has anything to do with it)

I'll continue my investigations, but I could use some help...
I am posting in case anybody has seen this behavior.
I cannot find it described in the lists.

Thanks for reading!

Sylvain Mazet.