Does legacy salt string support in Moodle 1.9.7 include support for non-salted passwords?

We have an active Moodle installation recently updated to 1.9.7. This site has never used password salts before. I want to enable password salts on the system, as Moodle recommends now for 1.9.7, but I am not sure if the legacy salt support setting includes support for non-salted passwords.

Reviewing the password sale do开发者_如何学编程cumentation on Moodle.org doesn't make it clear (to me) if the legacy salt support also includes support for no salt at all. My question is, will a zero length string salt for my legacy salt setting in config.php mean support for non-salted passwords?

E.g., can I add this in my config.php file:

$CFG->passwordsaltalt1 = '';
$CFG->passwordsaltmain = 'my new salt which is super secure';

and have current account holders still log in if their password isn't salted? I can't tell if this is right from their documentation and I'm wondering if anyone has successfully done this.

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I confirmed this with testing: Enabling a password salt does not affect unsalted logins, so you don't need to add a legacy entry for non-salted passwords.