System.IO.IOException: The process cannot access the file when calling Ren on the local disk storage

[intelligide]

When the Ren method is called from local disk storage, an exception is thrown:

System.IO.IOException: The process cannot access the file '<filename>' because it is being used by another process.
   at System.IO.FileSystem.DeleteFile(String fullPath)
   at Stowage.Impl.LocalDiskFileStorage.Rm(IOPath path, CancellationToken cancellationToken)
   at Stowage.PolyfilledFileStorage.RenFile(IOPath oldPath, IOPath newPath, CancellationToken cancellationToken)
   at Stowage.PolyfilledFileStorage.Ren(IOPath oldPath, IOPath newPath, CancellationToken cancellationToken)

It seems to come from the PolyfilledFileStorage.RenFile function, because it tries to delete the file while it's still open for reading.

Modifying the function as follows removes the error:

        private async Task RenFile(IOPath oldPath, IOPath newPath, CancellationToken cancellationToken = default) {
            using(Stream? src = await OpenRead(oldPath, cancellationToken)) {
                if(src != null) {
                    using(Stream dest = await OpenWrite(newPath, cancellationToken)) {
                        await src.CopyToAsync(dest);
                    }
                }
            }

            await Rm(oldPath); // <-- Move the file deletion outside the using scope
        }