Change the signature of odbc_connect

Hi, internals I'm currently working on renovating odbc_connect and odbc_pconnect. https://github.com/php/php-src/pull/12306 As a problem came up, I'm planning to create an RFC. I explain the problem briefly. In addition to the dsn, these functions have a credential argument. They are required and expect string. The following two cases are problematic here. 1. If the password is set to a blank character ('') 2. For authentication that does not require a password Since the current signature does not allow nulls, we cannot separate the handling of these cases and must give up on one of them. Therefore, I am thinking of changing the credential argument to be nullable and optional for these functions, like pdo. What do you think? Best regards. Saki