Harlen Batagelo f2c15f9deb
Fix crash when closing a window with Alt+F4 in multi-win Flutter on Windows (#161375)
Reopened from https://github.com/flutter/engine/pull/56501.

Fixes [#158450](https://github.com/flutter/flutter/issues/158450).

As mentioned in
[#158450](https://github.com/flutter/flutter/issues/158450), the crash
occurs because a destroyed object may be accessed if the window and view
have already been destroyed by the time `KeyEventCallback` is called.
This issue is not limited to the `Alt+F4` system key; it may also occur
if the window is closed using other key presses, such as pressing
`Enter` after navigating to a dialog's "Close" button.

This PR proposes a fix that checks whether the view ID is still valid
when the callback is invoked. If the view is invalid, the event is
skipped for that view.

A unit test has been added to assert that the `KeyEventCallback` is
invoked when the associated view is valid and not invoked when the view
is destroyed.

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2025-01-14 13:32:36 +00:00
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