Wayland: Wacom Stylus left-click on title bar of non-GNOME window causes window lost response to mouse/stylus clicks
Affected version
- OS: Manjaro test branch (rolling upgrade)
- GNOME/Mutter: 44.2-1
- Repro on XOrg: No
- Repro on Wayland: Yes
- Kernel version: 6.3.11-1-MANJARO
Bug summary
Steps to reproduce
- Login GNOME 44.2 Wayland session.
- Plug a Walcom stylus device to computer. In my case, I use a Wacom One stylus model CTL-472.
- Open Godot 4 or Godot 3.51 application (Verified on both Flatpak and system installation. Both have issues)
- On popup project list dialog, click title bar by clicking Walcom tablet with stylus pen tip.
What happened
When clicking Godot title bar with stylus, the behavior looks like below:
- Mouse cursor shape stuck in shape of moving (indicating Godot application window is moveable). However, Godot application window can't be dragged when moving stylus pen on Wacom tablet.
- When moving mouse device (just move without left cliking), Godot window immediately moves on desktop. It keeps moving only when I left click mouse button.
- After step 2, Godot window does not response to clicks, no matter mouse click or stylus pen tip. Neither title bar nor controls (buttons, menus, etc.) can be clicked.
Impact:
Given some applciations do not offer complete keyboard short-cuts like CTRL-Q, they can't be closed properly when this issue happens, which is annonying when there are unsaved changes.
Additional notes:
- To trigger the issue, the stylus click must be on title bar. Clicking within application window does not trigger this error. That means, there's a workaround, that I can carefully click title bar with only mouse, but do others with stylus. It works but easy to break.
- When this issue is triggerred, it causes same behavior on non-GNOME applications opened on same session, aka. none of them on desktop responses mouse/stylus clicks. I verified, that Aseprite and Pixelorama have the same issue. Meanwhile, apps like Firefox or any GNOME apps always work fine on Wayland. I didn't specifically test KDE applications.
- When this issue is triggered, both mouse and stylus clicks are impacted.
- The issue is gone by logging out current GNOME Wayland session. After login, it works until a stylue left-click on Godot window. Then the issue happens again.
- When starting GNOME 44 with XOrg, the issue does not happen. All apps works fine.
- Verified on Sway+Wayland session on same machine+device. The issue does not happen.
What did you expect to happen
When clicking Godot title bar with stylus, it should behave identical with mouse single click: window can be dragged and moved on screen. After moving, Godot window should still response to mouse click.
The issue was repro for first time by 2023-05-15, by that time Manjaro was upgrading GNOME from 43 to 44. After upgrading, this issue happens. I did some tests with help from Manjaro forum. Given GNOME+Xorg and Sway+Wayland works fine, appears the clue points to Mutter. I would like to confirm whether it's caused by any changes in Mutter in GNOME 44, which causes this issue.