Preflight Checklist

• I have read the Contributing Guidelines for this project.
• I agree to follow the Code of Conduct that this project adheres to.
• I have searched the issue tracker for a bug report that matches the one I want to file, without success.

Electron Version

40.6.1

What operating system(s) are you using?

Ubuntu

Operating System Version

Ubuntu 24.04.4 LTS

What arch are you using?

x64

Last Known Working Electron version

No response

Does the issue also appear in Chromium / Google Chrome?

No

Expected Behavior

Consider the attached gist, which attempts to display a full-screen window.
The expected behavior is that the window covers the screen exactly, and the two printed lines -- expected vs. actual window size -- match.

Actual Behavior

The window width and the window height are both 1 pixel too small. If you look closely, the rightmost pixel column and the bottom-most pixel rows aren't covered by the window.

Also, the output (on my machine) is:

Expected window size: 3440,1440
Actual window size: 3439,1439

Testcase Gist URL

https://gist.github.com/DanielSWolf/2f7fbdd1dac6be56dab17799a01fecb0

Additional Information

No response