Re: [PATCH v2 1/4] refs: add function to translate errors to strings

>> +char *ref_transaction_error_msg(enum ref_transaction_error err)
>> +{
>> +	const char *reason = "";
>> +
>> +	switch (err) {
>> +	case REF_TRANSACTION_ERROR_NAME_CONFLICT:
>> +		reason = "refname conflict";
>> +		break;
>> +	case REF_TRANSACTION_ERROR_CREATE_EXISTS:
>> +		reason = "reference already exists";
>> +		break;
>> +	case REF_TRANSACTION_ERROR_NONEXISTENT_REF:
>> +		reason = "reference does not exist";
>> +		break;
>> +	case REF_TRANSACTION_ERROR_INCORRECT_OLD_VALUE:
>> +		reason = "incorrect old value provided";
>> +		break;
>> +	case REF_TRANSACTION_ERROR_INVALID_NEW_VALUE:
>> +		reason = "invalid new value provided";
>> +		break;
>> +	case REF_TRANSACTION_ERROR_EXPECTED_SYMREF:
>> +		reason = "expected symref but found regular ref";
>> +		break;
>> +	default:
>> +		reason = "unkown failure";
>> +	}
>> +
>> +	return xstrdup(reason);
>> +}
>
> Why can't this return "const char *", without xstrdup()?