[FalconTechDev]

Closes #240

TryGetReparseDataBuffer rents a 16 KiB buffer from ArrayPool<byte>.Shared but only returned it when DeviceIoControl succeeded. For almost every directory the call fails because it is not a reparse point, the method returned early, and the buffer was dropped. So every ReadKind() on a directory allocated a new 16 KiB array.

The rent is now inside a try/finally so the buffer always goes back to the pool. DeviceIoControl has finished writing by then, so reusing it is safe.

I added a test, Windows only, that calls ReadKind() on a directory and checks it allocates less than 1 KiB per call. Without the fix it fails with 16,576 bytes per call. With the fix it passes, and the whole TruePath.Tests run on net8.0 is 471 passed, 0 failed on Windows 11. To run it locally I had to bump global.json to the SDK I have installed; that change is not in the PR. There is also a changelog entry under Unreleased.

I did not do the other idea from the issue (skip the reparse query when the ReparsePoint attribute is not set). I can do it as a follow up if you prefer that.

[ForNeVeR]

Thanks! I did some more digging and managed to reduce the allocations even more, but I'll mention your contribution in the release notes.