#1149113 qtmir: drop-down menus don't work for xwayland

#1149113#5
Date:
2026-09-26 18:42:30 UTC
From:
To:
Drop-down menus (such as in the menu bar or in combo boxes) don't show
for xwayland apps in Lomiri. You can still open menu items with the
keyboard if you know how many down arrow presses you need before
pressing enter.

When the qtmir stable release update was prepared in April, one patch
wasn't available yet:
0036_mirsurface-show-X11-override-redirect-windows-when-ready.patch

Test Case
========
1. Follow the instructions at https://wiki.debian.org/Lomiri to
install lomiri on Debian 13. If you are using a VM, follow the
additional instructions to enable 3D acceleration. If you are prompted
to choose a display manager, any choice is ok

2. Restart your computer. Log in to Lomiri. You may need to choose
Lomiri from a gear menu or similar on the login screen. You may need
to hold the Windows key to show the sidebar and app launcher the first
time you log in.

3. sudo apt install lomiri gtk-3-examples

4. Open a terminal and run
GDK_BACKEND=x11 gtk3-demo

Run the Combo Boxes demo. Verify that the drop down menus work correctly.

Other Info
=======
Affected apps:
- Google Chrome and Chromium still use xwayland by default
- Several apps that try to run the entire gui with elevated privileges
appear to use xwayland and are affected. Synaptic (.deb package
manager), gparted, calamares
- Most other apps using gtk3, gtk4, qt 5, or qt 6 aren't affected by default

This patch was applied as a stable update for Ubuntu 26.04 LTS in June 2026.
https://launchpad.net/bugs/2152852

Thank you,
Jeremy Bícha