Previously, we used messages greater than `WM_USER` to pass information
between `WindowsPlatform` and `WindowsWindow`. For example, to close a
window, we handled it as follows:
1. The window sends a message with `WM_USER + 2` to `WindowsPlatform`.
2. `WindowsPlatform`, upon receiving this message, casts the `lparam` to
`HWND` and closes the window.
According to Microsoft's documentation, it is safe to use values between
`WM_USER` and `0xBFFF` as messages. However, certain versions of
Microsoft's IME use `WM_USER + 2` for UNKNOWN purposes. This causes step
2 to be erroneously triggered. The IME window's `lparam` value could be
arbitrary, leading to an attempt to close an arbitrary `HWND` and
resulting in errors.
It is quite surprising that Microsoft indicates using `WM_USER + 2` is
safe, yet Microsoft itself breaks this convention. I mean, well done
Microsoft!
This PR addresses the issue by using the `wparam` with a specific random
value for validation purpose when sending the aforementioned message.
Before `WindowsPlatform` attempts to close the window, it will first
verify the `wparam` value.
Special thanks to @shenjackyuanjie for helping me on this.
Co-authored-by: shenjackyuanjie <3695888@qq.com>
Release Notes:
- Fixed weird panic when IME window is closing(#15185, #12563).
---------
Co-authored-by: shenjack <3695888@qq.com>
张小白andshenjackyuanjie
6af385c09e