ArraySource: Find with empty field condition returns all records

[liviakuenzli]

Situation: An array-based countries table with no record with country_iso_3_code being empty.

$result = $countryModel->find('list',
	array(
		'conditions' => array('country_iso_3_code' => ''),
	)
);

Expected $result to be empty, but it holds all entries of the table.

The following line is probably the culprint:

datasources/Model/Datasource/ArraySource.php

Line 253 in 47c4672

if ($value === '') {