[Bug]: setWindowOpenHandler changes default stylesheet for plain text files in dark theme

[ajafff]

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

>=22.0.0

What operating system are you using?

Windows

Operating System Version

Windows 10 Enterprise 22H2

What arch are you using?

x64

Last Known Working Electron version

21

Expected Behavior

Click on the link to open the plain text file in a new window.
Text should be readable, e.g. white text on dark background.

Actual Behavior

Text is not readable. It's white text on white background.
This seems to only happen if there is a setWindowOpenHandler. If you comment out that line, a dark background is applied.

Testcase Gist URL

https://gist.github.com/ajafff/8d9e8eb8cc0a7ec2297f2445c54f5526

Additional Information

No response

[ckerr]

This was introduced somewhere in v22.0.0-nightly.20220809...v22.0.0-nightly.20220810, most likely in #34526 from the announced breaking change of replacing the new-window event with webContents.setWindowOpenHandler().

[jeremyspiegel]

Is this the same as #36538?

[ckerr]

@jeremyspiegel probably not?

I agree they do look similar, but if 36538 was present in 21.3.1 and 37737 first appeared in v22.0.0-nightly.20220810 then they can't be the same issue 💫

[jeremyspiegel]

@ckerr sorry you're right. Using onclick="window.open('/popup.txt')" to open the window had the issue in v21, but using <a href="/popup.txt" target="_blank"> doesn't.

[jeremyspiegel]

I would guess that the underlying issue behind both is something about the change to use the transparent web preference to set the background color, introduced in #28054. Looks like that preference was only being set for the window.open case at that point, but then with #34526 it was then set for the <a target="_blank"> case as well.

[ajafff]

I agree that they look like duplicates. Feel free to close this one.
I would also like to see the window.open() case fixed, as that's what I'm actually using in my app. I just reduced it to <a target="_blank"> for this reproduction

[ckerr]

Well now I'm confused 😄

Can someone test & confirm whether or not 36538 is present in 21.3.1? If so, I don't see how these two tickets can be the same issue

[jeremyspiegel]

#36538 is present in 21.3.1.

There's probably a single underlying cause for both issues. The problematic code was likely introduced earlier in #28054, and only affected the window.open case, but not the <a target="_blank"> case. Then later the change #34526 in v22 caused the <a target="_blank"> case to also fall into the same problematic code path.

[dsanders11]

@ckerr, it's the same issue as #36538. I have the fix for these issues in #36914 but CI was giving me trouble with the tests, so I shelved it and then got sidetracked with other work. I've confirmed the fix in that PR fixes the gist provided in this issue. I'll pick it back up and see if I can make the tests happy.

[nornagon]

Duplicate of #36538.