How do I validate non-required fields?

[eluser]Skyscraper[/eluser]
Okay, I've figured out where the bug lies. In system/libraries/Form_validation.php line 335 you can see:

Code:

if (isset($_POST[$field]) AND $_POST[$field] != "")

This considers "not set" and "set but empty string" to be the same thing, so when _execute line 488 occurs, it sees you don't have "required" as a validation rule and does not apply your "min_length" rule because it thinks the value is "not set" (null) even though it's "set but empty string".

To fix this, simply comment out the second half of the conditional:

Code:

if (isset($_POST[$field])/* AND $_POST[$field] != ""*/)

(Or extend the Form_validation.php class)