User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:108.0) Gecko/20100101 Firefox/108.0

Steps to reproduce:

- On a multiple monitor setup, open a Firefox window on a KDE Plasma Wayland session
- Clicking the tab, drag the tab over to the other screen
- Let go of the tab on that screen

Actual results:

- Either
    - The preview image remains on screen until the mouse hovers over it (creating the window in expected results) or hovers over the original screen (creating the window on the original screen)*
    - The preview image remains on screen until the mouse hovers over it, or hovers too far away from the preview, and then disappears and no window is created.*
    - *If a Firefox window is already open on the second screen, the expected result occurs. If no Firefox window is open, the above results occur.

Expected results:

- A new Firefox window is created on that screen, populated with the tab that was dragged over

The Bugbug bot thinks this bug should belong to the 'Core::Widget: Gtk' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Can you please create a screencast of the issue?
https://fedoraproject.org/wiki/How_to_debug_Firefox_problems#Collect_information_for_a_bug_report
Thanks.

I have uploaded a screencast showing the problem. When the new tab is moved outside the Firefox window, a new window isn't created until (1) the left mouse button is released and (2) the cursor is moved over or away from the preview window. Moving the cursor around the preview (as shown in the video) won't do anything.

A new window should be created as soon as the left mouse button is released, without the need for step 2.

Interestingly, I only have this problem when Firefox is installed from Flathub (112.0.1). Firefox installed from Fedora Flatpaks (112.0.1-1.fc38) doesn't have this problem.

Is that flatpak only issues? Can you reproduce with plain mozilla bineries?
https://fedoraproject.org/wiki/How_to_debug_Firefox_problems#Testing_Mozilla_binaries
Thanks.

I followed the steps in the guide, but the stable version crashed immediately (segmentation fault), so I tried the beta version. It works better, but there are still two problems I noticed:

1. Moving the tab to the left, right, or bottom of the window works fine, but moving it above the window doesn't work most of the time.
2. The new window opens away from where I dragged the tab.

See the updated record.

(In reply to Laran from comment #6)

1. Moving the tab to the left, right, or bottom of the window works fine, but moving it above the window doesn't work most of the time.

That's interesting, I wonder if we're getting different events here. But without new D&D Wayland protocol we're blocked here IMHO.

2. The new window opens away from where I dragged the tab.

Wayland client doesn't have any control over window placement on desktop, that's managed by Wayland compositor. Right now without protocol changes we can't fix that.