[Bug]: offscreen render set background transparent does not work

[c-liang]

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

17.0.0

What operating system are you using?

Windows

Operating System Version

Windows 10 Version 21H1

What arch are you using?

x64

Last Known Working Electron version

14.2.3

Expected Behavior

background should transparent if background is #00000000

Actual Behavior

has a white background

Testcase Gist URL

No response

Additional Information

No response

[mlaurencin]

Thanks for reporting this and helping to make Electron better!

Would it be possible for you to make a standalone testcase with only the code necessary to reproduce the issue? For example, Electron Fiddle is a great tool for making small test cases and makes it easy to publish your test case to a gist that Electron maintainers can use.

Stand-alone test cases make fixing issues go more smoothly: it ensure everyone's looking at the same issue, it removes all unnecessary variables from the equation, and it can also provide the basis for automated regression tests.

I have tried creating a gist with your expected behavior, and have not been able to replicate the issue. I'm adding the blocked/need-repro label for this reason. After you make a test case, please link to it in a follow-up comment.

[c-liang]

Thanks for reporting this and helping to make Electron better!

Would it be possible for you to make a standalone testcase with only the code necessary to reproduce the issue? For example, Electron Fiddle is a great tool for making small test cases and makes it easy to publish your test case to a gist that Electron maintainers can use.

Stand-alone test cases make fixing issues go more smoothly: it ensure everyone's looking at the same issue, it removes all unnecessary variables from the equation, and it can also provide the basis for automated regression tests.

I have tried creating a gist with your expected behavior, and have not been able to replicate the issue. I'm adding the blocked/need-repro label for this reason. After you make a test case, please link to it in a follow-up comment.

https://gist.github.com/c-liang/29850810e9c5892587729d3d64a25761

electron 14.2.3

electron 17.0.0

view image with photoshop，electron 14.2.3 the background is transparent, but with 17.0.0 the background is pure white

[codebytere]

Bisected to v16.0.0-nightly.20210903...v16.0.0-nightly.20210906