See also #5 - We should really not use return parameters. Forms is already confusing enough.

As recommended there:

• Callers need to upgrade getInfo(...) to $info = getInfo(...) where this has not happened yet
• derived types need to return array $info in getInfo
• Callers need to add getMessage after isValid if they actually use the message
• derived types need to set $this->message before return if they actually set a message
• Let's draft a largely compatible V3 namespaced versions if the breaks proposed by @amulet1 in fix: Correct Horde_Form_Type::isValid() signature #5
• Let's keep more involved changes for V4 with PHP 8.4 baseline