[Pkg-xfce-devel] Bug#808053: lightdm-gtk-greeter: system keyboard layout not loaded due to failure to detect keyboard

[bunnie at kosagi.com (bunnie)]

Package: lightdm-gtk-greeter
Version: 1.8.5-2
Severity: normal

Dear Maintainer,

I have found a problem in setting the keyboard layout in the lightdm greeter
under certain hardware configurations. Looking around on the web it seems I'm
not the only one with the issue.

The problem happens when using a keyboard that fails to be recognized as
a keyboard by some autodetection system within debian. I found a similar
bug in the package "keyboard-configuration" where the script uses a 
series of tests to detect if a keyboard is attached, and if it doesn't
recognize the keyboard it silently fails to do anything.

The specific hardware setup I have is a Lenovo bluetooth keyboard model
FRU 03X8697 connected to the system via a bluetooth controller embedded
in an Azurewave AW-NB110H (AR9462 chipset). It enumerates in the system
as follows:

[   77.930984] input: ThinkPad Compact Bluetooth Keyboard with TrackPoint as /devices/soc0/soc/2100000.aips-bus/2184200.usb/ci_hdrc.1/usb1/1-1/1-1.3/1-1.3:1.0/bluetooth/hci0/hci0:21/0005:17EF:6048.0001/input/input4

The following experiment seems to demonstrate the failure to recognize
the BT keyboard properly.

1) plug in both a wired USB keyboard, and the BT wireless keyboard
2) reboot the system
3) wait for the BT keyboard to associate, and type into the lightdm login
box. The keyboard layout is default (qwerty-us in this case)
4) tap on the wired USB keyboard. The keyboard layout instantly changes
to the system layout after the first keystroke on the USB keyboard 
(dvorak in this case)
5) tap on the BT keyboard. The layout is still dvorak, and stays this
way.

The layout resets to qwerty every time lightdm-greeter is started, e.g.
if I log out, the keyboard layout resets to qwerty until I either tap
on the wired USB kebyoard, or I log in using the BT keyboard typing
in qwerty and the local xsession settings are applied to fix the layout.

So it seems that the system layout is not being updated until a "recognized"
keyboard input is applied; keyboards that fail to be recognized as keyboards
will not trigger the application of the system layout.

It would be nice if the layout could just be applied even if a recognized
keyboard isn't found, just in case the recognition failed. In looking at the
code used in the keyboard-configuration package, I can see how if a vendor
used non-standard naming conventions or if a keyboard were connected 
via BT, these keyboard would not be recognized as keyboards and the system
layout would fail to be updated. 

thanks for your consideration!

-b.

-- System Information:
Debian Release: 8.2
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: armhf (armv7l)

Kernel: Linux 3.19.0-00504-gb9c0464 (SMP w/4 CPU cores; PREEMPT)
Locale: LANG=en_US.utf8, LC_CTYPE=en_US.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages lightdm-gtk-greeter depends on:
ii  libc6                   2.19-18+deb8u1
ii  libcairo2               1.14.0-2.1
ii  libgdk-pixbuf2.0-0      2.31.1-2+deb8u3
ii  libglib2.0-0            2.42.1-1
ii  libgtk-3-0              3.14.5-1+deb8u1
ii  liblightdm-gobject-1-0  1.10.3-3
ii  libx11-6                2:1.6.2-3

Versions of packages lightdm-gtk-greeter recommends:
ii  desktop-base               8.0.2
ii  gnome-icon-theme-symbolic  3.12.0-1
ii  gnome-themes-standard      3.14.2.2-1
ii  policykit-1                0.105-8

lightdm-gtk-greeter suggests no packages.

-- Configuration Files:
/etc/lightdm/lightdm-gtk-greeter.conf changed:
[greeter]
background=/usr/share/images/desktop-base/login-background.svg
theme-name=Adwaita
xft-antialias=true
xft-hintstyle=hintfull
xft-rgba=rgb
show-indicators=~language;~session;~power;~a11y
keyboard=onboard


-- no debconf information