Using the Zend_Validate_Hostname with the default setting of not allowing local hostnames will produce incorrect errors when given an invalid local network name such as machine_local:

1. The isValid() method on line 413 checks if the hostname is a valid local network name and correctly sets an error if not.
2. Regardless of the result above, line 418 does a check if local names are allowed at all and so also sets an error.
3. The result is these errors, both of which cannot be correct simultaneously:

- 'machine_local' does not appear to be a valid local network name - 'machine_local' appears to be a local network name but local network names are not allowed

Attached is a patch to correct line 418 from

to