1644161 - Drop-downs with custom width resize on mouse movement

Status: RESOLVED DUPLICATE of bug 1640567

(Core :: DOM: UI Events & Focus Handling, defect, P3)

Description

[Wout B]

Attachment: simplescreenrecorder-2020-06-08_17.23.50.mp4

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:77.0) Gecko/20100101 Firefox/77.0

Steps to reproduce:

I'm using Firefox 77.0-1 (with MOZ_USE_XINPUT2=1, MOZ_ENABLE_WAYLAND=1 and WebRender turned on) and Sway 1.4-2 on Debian Unstable.

1. Click on a drop-down with a custom width.
2. Move the mouse cursor.

Actual results:

See attached video.

Expected results:

The drop-down stays as wide, like in previous Firefox versions.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

Comment 2

[Jim Blandy :jimb]

Wow, that looks pretty irritating. Thank you for reporting!

Re-categorizing so this can get the attention from the right folks.

Comment 3

[Wout B]

This only happens with Wayland, at least in Sway and GNOME Shell.

Comment 4

[John Dai[:jdai]]

Dear reporter,
I can't reproduce the issue from my ubuntu platform. Perhaps the issue only happens in one of your settings or platform? Could you use a clean profile without all the settings and test it again? Thank you

Comment 5

[Wout B]

The same thing happens in a clean profile.

Comment 6

[Emilio Cobos Álvarez (:emilio)]

I think this has been fixed on Nightly already, could you try a build from https://nightly.mozilla.org and test it?

Comment 7

[Wout B]

This still happens in Nightly.

I could even reproduce this in a new VM with Debian. All I've done in that VM is:

1. Edit /etc/apt/sources.list to use unstable instead of buster.
2. sudo apt update
3. sudo apt full-upgrade
4. sudo apt --purge autoremove
5. sudo apt install gdm3 sway firefox
6. sudo apt clean
7. Edit /etc/environment to have MOZ_USE_XINPUT2=1 and MOZ_ENABLE_WAYLAND=1.
8. Reboot.
9. Open Firefox.
10. Go to https://jsfiddle.net/mt5xwvjr/.

Comment 8

[Darkspirit]

I ran mozregression and found bug 1640567.