Moving cursor from addon popup to website keeps tab sidebar showing in compact mode

[galfonso99]

Captchas

• I have read the instructions.
• I have searched existing issues and avoided creating duplicates.
• I am not filing an enhancement request.
• I have checked that this issue cannot be reproduced on Mozilla Firefox.
• I have checked that this issue can be reproduced once I removed all my Mods and Custom CSS.

What happened?

When I click on. a addon popup that is wide enough I often move the cursor from the popup to the viewport of the website without even passing over the tab sidebar. This causes the side bar to not hide. I assume this is because the code expects the cursor to move from the sidebar to somewhere away from the sidebar for it to hide, but by skipping the sidebar area using a addon popup the sidebar doesn't hide like I would expect. As it is currently I have to brind the cursors back to the sidebar area and off again for it to trigger the hide condition.

Steps to reproduce:
0. Be on Mac OS (My guess is it is not exclusive to MacOS)

1. Open Zen with a brand new profile
2. Put on compact mode
3. Move tab sidebar to the right
4. Install tab session manager from firefox addons (or any with a wide addon popup)
5. Click on the addon (Popup should now 'pop up')
6. Hover over the popup and move the mouse over to the web page viewport without passing over the sidebar
7. The sidebar stays even though it is on compact mode and it should hide

Version

1.11.4b

What platform are you seeing the problem on?

macOS - Intel

What component is this issue related to?

Tabs

Relevant log output if applicable