Ctrl+Shift and other layout switching combinations stop working as modifiers

[Monk]

Binary package hint: xorg

The bug is live in intrepid, 8.10.

It is possible to set combination like "Ctrl+Shift" the keyboard layout
switcher privatizes it as the shortcut for switching layouts, and disallows all
other programs to use it as modifier.

Steps to reproduce:
0. Login to GNOME (the steps below are for 2.24, but should be similar for
other versions).
1. Open "Keyboard preferences" in Keyboard layout indicator applet.
2. Go to Layouts.
3. Add some keyboard layouts.
4. Click "Other Options".
5. Under "Layout switching", check "Ctrl+Shift" change layout.
6. Open Firefox.
7. Open several tabs with Ctrl+T.
8. Switch forward through them with multiple "Ctrl+Tab". Notice that everything
is ok.
9. Try to switch backward through them with multiple "Ctrl+Shift+Tab"...

Actual results:
Exactly at moment when you press down Ctrl and Shift, keyboard layout changes;
after you press Tab, without letting Ctrl and Shift off, Firefox switches one
tab forward instead of one tab backward.

Expected results:
Firefox should go one tab back.
Layout should not change.

Overall, the layout should change not at the time when you press down Ctrl and
Shift, but only at the time when you let go one of them, and only if you didn't
use this combination as modifier for another key.

Does this happen every time?
Yes.

Other information:
In windows, everything is working exactly as desired - layouts are changed only
at the time when you let go the combination.

Corresponding bug against X.Org is unsolved since 2004: http://bugs.freedesktop.org/show_bug.cgi?id=865

This is one of the main issues that prevent Ubuntu to be used internationally.

[lspci]
00:00.0 Host bridge [0600]: Intel Corporation 82G33/G31/P35/P31 Express DRAM Controller [8086:29c0] (rev 02)
     Subsystem: Giga-byte Technology Device [1458:5000]
01:00.0 VGA compatible controller [0300]: ATI Technologies Inc RV670PRO [Radeon HD 3850] [1002:9505]
     Subsystem: ATI Technologies Inc Device [1002:e630]

[Bryce Harrington (bryce)]

[This is an automated message]

Hi monkbel,

Please attach the output of `lspci -vvnn`, and attach your /var/log/Xorg.0.log file from after reproducing this issue. If you've made any customizations to your /etc/X11/xorg.conf please attach that as well.

[Bryce Harrington (bryce)]

We're closing this bug since it is has been some time with no response from the original reporter. However, if the issue still exists please feel free to reopen with the requested information. Also, if you could, please test against the latest development version of Ubuntu, since this confirms the bug is one we may be able to pass upstream for help.

[Monk (monkbel)]

Hi Bryce,

sorry for the delay.

Here are the attaches.
Notice that I reproduced the issue (with steps from the original post) at 21:20 local time, but it is not reflected in the log.

I am using up-to-date version of 8.10. I am not sure if I will be able to install 9.04 alpha soon.

[Monk (monkbel)]

I believe that my xorg.conf doesn't have relevant customizations but I attach it just in case.

btw I believe that the issue will be reproducible in the latest dev release as well, since corresponding bugs in Gnome and Xorg are not marked as fixed.

[Eugene (lisitsky)]

I have the same trouble - swiching occurs on press, but not on release.
I looked events with xev utility:

$ xevKeyPress event, serial 34, synthetic NO, window 0x4600001,
    root 0x7b, subw 0x0, time 52934768, (315,42), root:(1081,421),
    state 0x2000, keycode 37 (keysym 0xffe3, Control_L), same_screen YES,
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False

KeyPress event, serial 34, synthetic NO, window 0x4600001,
    root 0x7b, subw 0x0, time 52935785, (315,42), root:(1081,421),
    state 0x2004, keycode 50 (keysym 0xfe0a, ISO_Prev_Group), same_screen YES,
    XKeysymToKeycode returns keycode: 37
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False

PropertyNotify event, serial 34, synthetic NO, window 0x4600001,
    atom 0x161 (XKLAVIER_STATE), time 52935792, state PropertyNewValue
                                                                                                                                           <--- layout changes here
PropertyNotify event, serial 34, synthetic NO, window 0x4600001,
    atom 0x161 (XKLAVIER_STATE), time 52935796, state PropertyNewValue

KeyRelease event, serial 34, synthetic NO, window 0x4600001,
    root 0x7b, subw 0x0, time 52936895, (315,42), root:(1081,421),
    state 0x4, keycode 50 (keysym 0xfe0a, ISO_Prev_Group), same_screen YES,
    XKeysymToKeycode returns keycode: 37
    XLookupString gives 0 bytes:
    XFilterEvent returns: False

KeyRelease event, serial 34, synthetic NO, window 0x4600001,
    root 0x7b, subw 0x0, time 52940025, (315,42), root:(1081,421),
    state 0x4, keycode 37 (keysym 0xffe3, Control_L), same_screen YES,
    XLookupString gives 0 bytes:
    XFilterEvent returns: False
...

Is it possible to fix this? To move switch to KeyRelease event?

[Denis Sitnitsa (zeroed)]

Up

[Denis Sitnitsa (zeroed)]

Seems like this problem will never be resolved =)

[Timur Khanipov (tkhanipov)]

I confirm the issue. I am using Ubuntu 9.04 and my layout is switched by Ctrl+Shift. When I try to reopen the last closed tab in Firefox using the Ctrl+Shift+T hotkey all I get is switching languages and opening new tab (like via Ctrl+T).

[bizdelnick (bizdelnick)]

I confirm this issue too. It is not specific to some distribution, I met it on all Linux distros I used (openSUSE 10.1-11.1, Mandriva 2009.0-2010.0, Ubuntu 8.04-9.04 etc.) It is also not specific to some combination, the same happens when using Alt+Shift, Alt, Ctrl and any other possible keys for switching layout.