Comment 0 for bug 1797352

On Ubuntu 18.04 (bionic) I am not able to use Ctrl+Shift, Control+Alt and other combinations which include only modifier keys to switch input source (works in gnome shell).

I solved this problem by making patch for gnome-flashback.
There problem with function gtk_accelerator_valid(keyval, modifiers), which always return False for such combinations. So I`ve just removed this validation.

Patch also include fix for modifier release event.

My OS is:
Description: Ubuntu 18.04.1 LTS
Release: 18.04

Package: gnome-flashback
Version: 3.28.0-1ubuntu1.2
Priority: optional
Section: gnome
Maintainer: Ubuntu Developers <email address hidden>
Original-Maintainer: Debian GNOME Maintainers <email address hidden>
Installed-Size: 921 kB
Provides: notification-daemon, polkit-1-auth-agent
Depends: gnome-flashback-common (= 3.28.0-1ubuntu1.2+switch+is~86), libatk1.0-0 (>= 1.12.4), libc6 (>= 2.4), libcairo2 (>= 1.10.0), libcanberra-gtk3-0 (>= 0.25), libgdk-pixbuf2.0-0 (>= 2.22.0), libglib2.0-0 (>= 2.55.2), libgnome-bluetooth13 (>= 3.12.0), libgnome-desktop-3-17 (>= 3.17.92), libgtk-3-0 (>= 3.22.0), libibus-1.0-5 (>= 1.5.2), libpango-1.0-0 (>= 1.14.0), libpangocairo-1.0-0 (>= 1.14.0), libpolkit-agent-1-0 (>= 0.99), libpolkit-gobject-1-0 (>= 0.99), libpulse-mainloop-glib0 (>= 0.99.1), libpulse0 (>= 0.99.1), libupower-glib3 (>= 0.99.0), libx11-6 (>= 2:1.2.99.901), libx11-xcb1, libxcb-randr0 (>= 1.1), libxext6, libxfixes3, libxi6 (>= 2:1.2.99.4), libxkbfile1, libxrandr2 (>= 2:1.5.0)
Recommends: dbus, gnome-settings-daemon (>= 3.26)
Suggests: gnome-power-manager
Homepage: https://wiki.gnome.org/Projects/GnomeFlashback
Download-Size: 261 kB
APT-Manual-Installed: yes
Description: helper application for the GNOME Flashback session
 This package provides a helper application for the GNOME Flashback
 desktop session. This application:
  - provides the Logout, Reboot and Shutdown dialogs;
  - provides the Sound, Bluetooth and Power tray applets;
  - implements screenshot and screencast functionality;
  - implements input source switching functionality;
  - draws desktop background;
  - implements other functionality which was previously handled by
    gnome-settings-daemon.