As of PHP8, passing `null` to `strlen()` is deprecated. The `$company_tagline` var is assigned to the output of the `get_the_company_tagline` function, which returns `null` under certain conditions.

With this change, we're checking that `$company_tagline` exists: continue if it does, but if it's `null` or doesn't exist, return early.

To be safe, let's check for `null` or `0` (string) explicitly.