1707237 - Window height exceeds monitor dimensions on Windows

Status: RESOLVED DUPLICATE of bug 1614218

(Core :: Widget: Win32, defect)

Description

[julkali]

Attachment: Notice the top white border

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:88.0) Gecko/20100101 Firefox/88.0

Steps to reproduce:

I cannot say if I actively made some change that triggered this problem, it has been present for months and I only got around to adding an issue now.

Actual results:

I am running a dual-monitor setup on Windows 10, where the two screens are aligned vertically. The lower one has dimensions 1920x1080, while the upper one is UHD (3840x2160).
Now, whenever Firefox is open and maximized on the lower screen with no window being open on the upper screen, there is a thin white line visible on the upper monitor. Although the attached screenshot doesnt really properly the border between the two screens, you can still clearly see the white bar at the top.
Interestingly enough, the bar is gone when switching into fullscreen (F11) and back, until the next launch of FF.

Expected results:

The upper monitor should not show maximized windows on the lower monitor.

Comment 1

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

The Bugbug bot thinks this bug should belong to the 'Core::Widget: Win32' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.