Bug#1117976: console-setup: Keyboard level 4 remains locked if AltGr and Shift are released in incorrect order

[Rimas Kudelis <rimas@kudelis.lt>]

Package: console-setup
Version: 1.240
Severity: important

Dear Maintainer,

When freshly installing Debian 13, I have configured it to use 
Lithuanian keymap at startup. A secondary US keymap was also configured 
for me by default.

The Lithuanian keymap is similar to the US keymap, but replaces the 
characters in the top row with accented Lithuanian letters, moving 
digits to level 3 (AltGr) and special characters to level 4 
(AltGr+Shift).

When I tried using text terminal yesterday, I noticed that Level 4 tends 
to lock if I don't pay close attention to how I use it. For example, to 
enter &&, I need to use level 4. So if I enter it by pressing AltGr, 
then Shift, then pressing and releasing key 7 (twice), then releasing 
Shift, then releasing AltGr, all seems fine.

However, if I release AltGr before Shift (as I normally do), Level 4 
remains in effect, and I couldn't find a way to get out of it other than 
pressing ^C to cancel the command I was typing and logging out of the 
affected console by pressing ^D.

I believe this might be considered an important/major bug, because it 
impedes console usage in a major way and is probably not configurable 
separately from the X11/Wayland keymap, which is all done as a part of 
the normal setup experience.

Cheers,
Rimas

-- System Information:
Debian Release: 13.1
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, 
'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 6.12.48+deb13-amd64 (SMP w/12 CPU threads; PREEMPT)
Kernel taint flags: TAINT_WARN
Locale: LANG=lt_LT.UTF-8, LC_CTYPE=lt_LT.UTF-8 (charmap=UTF-8), LANGUAGE 
not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages console-setup depends on:
ii  console-setup-linux     1.240
ii  debconf [debconf-2.0]   1.5.91
ii  keyboard-configuration  1.240
ii  xkb-data                2.42-1

console-setup recommends no packages.

Versions of packages console-setup suggests:
ii  locales                    2.41-12
ii  sysvinit-utils [lsb-base]  3.14-4

Versions of packages keyboard-configuration depends on:
ii  debconf [debconf-2.0]   1.5.91
ii  liblocale-gettext-perl  1.07-7+b1
ii  xkb-data                2.42-1

Versions of packages console-setup-linux depends on:
ii  init-system-helpers     1.69~deb13u1
ii  kbd                     2.7.1-2
ii  keyboard-configuration  1.240

console-setup-linux suggests no packages.

Versions of packages console-setup is related to:
pn  console-common        <none>
pn  console-data          <none>
pn  console-tools         <none>
ii  gnome-control-center  1:48.4-1~deb13u1
ii  kbd                   2.7.1-2
ii  systemd               257.8-1~deb13u2

-- debconf information:
  keyboard-configuration/unsupported_options: true
  keyboard-configuration/unsupported_config_layout: true
* keyboard-configuration/switch: No temporary switch
  console-setup/charmap47: UTF-8
* keyboard-configuration/optionscode: 
grp:alt_shift_toggle,grp_led:scroll
  console-setup/fontsize-text47: 8x16
  keyboard-configuration/unsupported_config_options: true
  debian-installer/console-setup-udeb/title:
  keyboard-configuration/ctrl_alt_bksp: false
  keyboard-configuration/unsupported_layout: true
* keyboard-configuration/layoutcode: lt,us
  console-setup/fontface47: Fixed
* keyboard-configuration/xkb-keymap: lt
  console-setup/guess_font:
* keyboard-configuration/layout:
  console-setup/fontsize: 8x16
  console-setup/use_system_font:
  console-setup/framebuffer_only:
* keyboard-configuration/modelcode: pc105
  console-setup/store_defaults_in_debconf_db: true
* keyboard-configuration/compose: No compose key
* keyboard-configuration/model: Įprastinė PC 105 klavišų
* keyboard-configuration/variantcode: ,altgr-intl
* keyboard-configuration/toggle: Alt+Shift
* keyboard-configuration/store_defaults_in_debconf_db: true
  console-setup/fontsize-fb47: 8x16
* keyboard-configuration/variant: Lietuvių
* keyboard-configuration/other:
* keyboard-configuration/altgr: The default for the keyboard layout
  console-setup/codesetcode: Lat7
  console-setup/codeset47: # Latin7 - Lithuanian; Latvian; Maori and 
Marshallese