The rules_help function has a return type of String but the method it returns (RulesHelpHooks::help()) can return NULL.
rules_help
String
RulesHelpHooks::help()
This can cause a PHP error for when the hook is invoked for non help.page.rules routes.
help.page.rules
Active
4.0
Rules Core
Patch attached
Issue #3489848 by steyep: TypeError in rules_help
Thanks. I had meant to leave the signature of the legacy hook functions unchanged - I don't know why I missed that one.
Automatically closed - issue fixed for 2 weeks with no activity.