Browser becomes unresponsive after dragging-and-dropping files.

[x0wllaar]

UPDATE: it's this bug, which is being fixed by both Google and KDE: https://bugs.kde.org/show_bug.cgi?id=482142 and https://issues.chromium.org/issues/329703410

System Details

• OS: Fedora 40
• Thorium Version 122.0.6261.132 AVX2

Problem
The browser stops responding to mouse after dragging-and-dropping (DnD) a file onto a DnD area on a website.

Additional Notes
To reproduce:

1. Run Thorium on KDE Plasma 6 Wayland
2. Go to e.g. https://jsfiddle.net/kmturley/5tduyx6q/, but this happens on all websites
3. Drag a file from a file manager onto the DnD area
4. Observe the browser not responding to mouse events.
5. Keyboard still works, window still updates, it's only the mouse that gets disabled.

Does not reproduce on Chrome Unstable.
Hm, I managed to repro on Chrome Unstable, it looks like an upstream bug.

Possibly relevant portion of debug logs:

$ cat ./chrome_debug.log | grep -A 10 -B 10 -i dragdrop
interface: org.freedesktop.portal.Settings
member: SettingChanged
sender: :1.27
signature: ssv
serial: 5333

string "org.kde.VirtualKeyboard"
string "visible"
variant   bool false

[88206:88206:0411/234445.304745:VERBOSE1:wayland_data_drag_controller.cc(433)] OnDragDrop window=1
[88206:88206:0411/234445.304847:VERBOSE1:wayland_pointer.cc(81)] Ignoring enter event received during dnd session.
[88206:88206:0411/234445.537637:VERBOSE1:wayland_pointer.cc(133)] Ignoring motion event received during dnd session.
[88206:88206:0411/234445.544613:VERBOSE1:wayland_pointer.cc(133)] Ignoring motion event received during dnd session.
[88206:88206:0411/234445.552628:VERBOSE1:wayland_pointer.cc(133)] Ignoring motion event received during dnd session.
[88206:88206:0411/234445.559580:VERBOSE1:wayland_pointer.cc(133)] Ignoring motion event received during dnd session.
[88206:88206:0411/234445.567618:VERBOSE1:wayland_pointer.cc(133)] Ignoring motion event received during dnd session.
[88206:88206:0411/234445.574599:VERBOSE1:wayland_pointer.cc(133)] Ignoring motion event received during dnd session.
[88206:88206:0411/234445.582586:VERBOSE1:wayland_pointer.cc(133)] Ignoring motion event received during dnd session.
[88206:88206:0411/234445.590382:VERBOSE1:wayland_pointer.cc(133)] Ignoring motion event received during dnd session.
[88206:88206:0411/234445.597597:VERBOSE1:wayland_pointer.cc(133)] Ignoring motion event received during dnd session.

It looks like the browser gets confused whether the drag and drop session ended or not?

[JadenJSJ]

It seems that I have the same issue.
It only seems to happen when I am running wayland and have the --ozone-platform=wayland flag.
Try removing it.
However I didn't get the "Ignoring motion event received during dnd session." that you mentioned in the terminal

I personally really need the flag because I use pinch to zoom alot. Which does not work without that flag.