Bug 297202 – [WebDriver] REGRESSION(297613@main) Test suite deadlocks in call to `switchToBrowsingContext` in `switch_to_window/switch.py` dialog tests

• Status: NEW
• Component: WebDriver

[Lauro Moura]

Test case:
imported/w3c/webdriver/tests/classic/switch_to_window/switch.py::test_finds_exising_user_prompt_after_tab_switch[alert]

Test steps:

* Creates a new window (but does not select it) - Works
* Executes an alert in the current window - Works
* Switches to the new window (asserts success) - Works
* Checks if we raise `NoSuchAlertException` - Works
* Closes new window - Works
* Switches back to the original window (asserts success) - TIMEOUT
* Accepts the dialog opened in the original window - Never reached

Then, during teardown, we get another identical `switchToBrowsingContext` call to the one that timed out before. As we don't have a timeout here, the test run gets stuck and we deadlock.

Checking the IPC, in these timing out calls, the `WebAutomationSessionProxy::FocusFrame` message never reaches its handler despite `WebAutomationSession` sending it. Still need to check the internals of `sendWithAsyncReplyToProcessContainingFrameWithoutDestinationIdentifier` to see where it's dropping it.

It also might be alert-related, as removing the alert call skips the timeout and the teardown issue.

[Lauro Moura]

Per bug297670, which reverted 297613, this also affected other ports.

[Lauro Moura]

(In reply to Lauro Moura from comment #1)
> Per bug297670, which reverted 297613, this also affected other ports.

I meant, it reverted 297613@main

[Radar WebKit Bug Importer]

<rdar://problem/158859509>