API: Contribution is_test doesn't work

Make a call such as:

$params = array(
'return' => "id",
'invoice_id' => $invoice_id,
'contribution_status_id' => "Pending",
'is_test' => 1
);
$result = civicrm_api3('Contribution', 'get', $params);

And you get zero results. This is because the SQL query that gets fired actually ends up having contribution_test = 0 AND is_test = 1 in the WHERE clause. I'm guessing it expects contribution_test as the correct parameter name.

So if instead of the parameter 'is_test' you put
'contribution_test' => 1
then it works as expected and returns results.

In the API explorer it gave me the 'is_test' parameter to put in there, so that got me tripped. It would be nice to either fix this in the API explorer/documentation or in the actual API implementation. Whichever suits better.