Editor.Plugins.Tools.Modeling.EditorMode.ExtrudePolygons.* test cases fail in headless mode due to stylus error log.

Hello!

In UE 5.5 Preview, new stylus code was introduced, which can cause a test failure in an unrelated test suite, Editor.Plugins.Tools.Modeling.EditorMode.ExtrudePolygons.*.

The test indirectly invokes FWindowsStylusInputInterface::CreateInstance, which attempts to get a window handle. While this works in the editor, when run with -NullRHI, it is not possible to get a window handle. As a result, this code generates an error log, which is interpreted as a test failure.

We have addressed the test failure by downgrading the error log to a warning. We'd be interested in getting this, or an alternative fix, into the mainline.

Thanks!

Steps to Reproduce

.\Engine\Binaries\Win64\UnrealEditor-Cmd.exe <insert project> -ExecCmds="Automation RunTests ExtrudePolygon;Quit" -nosplash -NullRHI -stdout

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Note the error log causing the test failure:

LogStylusInput: Error: WindowsStylusInputInterface: Could not get native window handle.