fix: getting focused window with destroyed webContents

[codebytere]

Description of Change

Closes #33326.

It's possible that getFocusedWindow could be called while a window is being destroyed or closed - if this is the case & its webContents is destroyed, a call to that method will result in an Object has been destroyed error due to

electron/lib/browser/api/browser-window.ts

Line 75 in 77297f3

if (window.isFocused() || window.isDevToolsFocused()) return window;

.

We fix this by ensuring that getFocusedWindow only includes windows with currently-alive webContents.

Tested with https://gist.github.com/d7433e132a56679832f37a9446d4530c

Checklist

• PR description included and stakeholders cc'd
• npm test passes
• tests are changed or added
• PR release notes describe the change in a way relevant to app developers, and are capitalized, punctuated, and past tense.

Release Notes

Notes: Fixed a potential crash in Browser.getFocusedWindow() when child windows are closed.

[pushkin-]

Thanks for the quick PR.
In my specific case by the way, I am calling BrowserWindow::destroy() and the crash I'm getting suggests that webContents is actually null. Should we check that in addition to isDestroyed()?

[jkleinsc]

Can you rebase this PR? That should resolve the failing CI.

[zcbenz]

Code looks good to me.

[pushkin-]

@codebytere Following up - can you speak to my comment above. Is this issue fixed when you call win.destroy() instead of close? I'm getting a crash about webContents being null which still seems like it'd be possible with your fix.

[codebytere]

@pushkin- yes - it should work both for closed and destroyed windows. I just added an extra safeguard, though, similar to what we have in our window test helpers

[release-clerk]

Release Notes Persisted

Fixed a potential crash in Browser.getFocusedWindow() when child windows are closed.

[trop]

I was unable to backport this PR to "16-x-y" cleanly;
you will need to perform this backport manually.

[trop]

I was unable to backport this PR to "17-x-y" cleanly;
you will need to perform this backport manually.

[trop]

I was unable to backport this PR to "18-x-y" cleanly;
you will need to perform this backport manually.

[codebytere]

/trop run backport-to 18-x-y

[trop]

The backport process for this PR has been manually initiated - sending your PR to 18-x-y!

[trop]

I have automatically backported this PR to "18-x-y", please check out #33538

[codebytere]

/trop run backport-to 17-x-y,16-x-y

[trop]

The backport process for this PR has been manually initiated - sending your PR to 17-x-y!

[trop]

The backport process for this PR has been manually initiated - sending your PR to 16-x-y!

[trop]

I have automatically backported this PR to "17-x-y", please check out #33539

[trop]

I have automatically backported this PR to "16-x-y", please check out #33540