HTTPStatusCode: http.StatusBadRequest,
	},
	ErrPOSTFileRequired: {
		Code:           "InvalidArgument",
		Description:    "POST requires exactly one file upload per request.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrSignatureVersionNotSupported: {
		Code:           "InvalidRequest",

	if len(toMerge) == 0 {
		return policy.Policy{}, errNoSuchPolicy
	}
	return policy.MergePolicies(toMerge...), nil
}

// GetPolicyDoc - gets the policy doc which has the policy and some metadata.
// Exactly one policy must be specified here.
func (store *IAMStoreSys) GetPolicyDoc(name string) (r PolicyDoc, err error) {
	name = strings.TrimSpace(name)
	if name == "" {
		return r, errInvalidArgument
	}

	if err = checkPathLength(filePath); err != nil {
		return nil, err
	}

	buf, _, err = s.readAllData(ctx, volume, volumeDir, filePath, false)
	return buf, err
}

// ReadFile reads exactly len(buf) bytes into buf. It returns the
// number of bytes copied. The error is EOF only if no bytes were
// read. On return, n == len(buf) if and only if err == nil. n == 0
// for io.EOF.
//

			// v1.1 does not have CRC.
			if minor < 2 {
				if err := readMore(want); err != nil {
					return nil, err
				}
				return buf[:want], nil
			}

			// CRC is variable length, so we need to truncate exactly that.
			wantMax := want + msgp.Uint32Size
			if wantMax > size {
				wantMax = size
			}
			if err := readMore(wantMax); err != nil {
				return nil, err
			}

			if int64(len(buf)) < want {