document.hasFocus() can return true for multiple windows being opened

[jrieken]

Testing #122200

• have multiple windows of VS Code open
• enable or disable window.nativeTabs
• 💩 each window shows a model dialog about needing to restart
• select restart in each window
• 🐛 restart doesn't happen

Untitled.mov

[bpasero]

We probably have this issue for any setting that the relauncher.contribution.ts listens to. Will see if I can just show the dialog in the active window.

[bpasero]

Turns out we already check for the window having focus or not:

vscode/src/vs/workbench/services/host/electron-sandbox/nativeHostService.ts

Line 36 in b8a3208

return document.hasFocus();

I cannot reproduce this but if document.hasFocus() returns true for multiple windows being opened, I suspect an Electron issue. I am open to changing the method to check for another property, but having it return sync was one of the main reasons I use document.hasFocus(), we use the same in web btw.

//cc @rzhao271

[bpasero]

@jrieken are you able to reliably reproduce? Any special window manager installed?

[jrieken]

Yeah, it is tricky... So, the first time I set "window.nativeTabs": true it works. Then I comment out this setting and the modal shows. First only for the current window and a bit later (~2sec?) for all windows. Once that happened it will always reproduce

[bpasero]

Oh yeah I can reproduce. Steps:

• (use a fresh user data dir to start clean)
• open 3 folders in 3 windows
• enable native tabs and restart
• disable native tabs

=> 🐛 each window shows the dialog

[bpasero]

Reported as electron/electron#28897

[deepak1556]

Temporary workarounds:

1. Start the window with show: false and window.show()
2. webContents.removeAllListeners('load-url')

[rzhao271]

Ok I finally built electron 12 source on the Mac.
I was about to let it build overnight with goma, but for some reason I got logged out of the server. I wouldn't be surprised if this has to do with power settings on my device.

With this build, I commented out the line that initially focuses the frame.
I then opened @bpasero's Fiddle from electron/electron#28897 with that build, and noticed that the top-most frame that showed up had focus initially true, and the other two frames had focus initially false.

I then tested electron/electron#25287 with the build, and found out that that Fiddle still works perfectly fine, too.

Therefore, I believe we can remove most of https://github.com/electron/electron/pull/25292/files and just let Chromium handle the focusing again.

[rzhao271]

@deepak1556's upstream fix is here: electron/electron#29204, and the backport for that fix is here: electron/electron#29235

[bpasero]

Given #125122 and other related issues, we will be going back to Electron 12.0.7 for recovery. Hence reopening this issue, even though technically it is fixed for insiders because we are not going back there.