writeErrorResponse(ctx, w, apiErr, r.URL)
		return
	}
	if checksum != nil && checksum.Type.Trailing() {
		// Not officially supported in POST requests.
		apiErr := errorCodes.ToAPIErr(ErrMalformedPOSTRequest)
		apiErr.Description = fmt.Sprintf("%s (%v)", apiErr.Description, errors.New("Trailing checksums not available for POST operations"))