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

15.3.1

What operating system are you using?

Windows

Operating System Version

Windows 11 with latest updates

What arch are you using?

x64

Last Known Working Electron version

15.3.0

Expected Behavior

If web server response a blob with file name specified in Content-Disposition with encoding, for example:
server response header include:
content-disposition: "attachment; filename*=UTF-8''filename.xlsx"
Electron should pass server response header Content-Disposition as it is in XMLHttpRequest so app JavaScript can handle it correctly, should not change it's value.

Actual Behavior

Due to the change in the PR: #31669
response header value content-disposition will be replaced if the value contains encoding info.
content-disposition: "attachment; filename*=UTF-8''filename.txt"
will be changed to:
content-disposition: "attachment; filename=\"filename.txt\""
If I inspect web request with dev tool, I can see the network panel shows the response header with original value, but in the JS XMLHttpRequest handler, I can only get the altered value instead, this should not happen as it is not expected when we need to handle the file name in the header with JS code.

Testcase Gist URL

No response

Additional Information

The commit:
24b02d6
The PR:
#31669
Some doc online:
https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Disposition