Issue with pseudo fields when column is null

I wouldn't call this a bug, per se, but it's definitely an unnecessary performance issue that should be fixed.

• You have a table (A) with a field (F) that is a List that is set to Get Options from Database (advanced) from table (B)
• Field F is set to null in all records in the table.
• You run getRecords() on table A with loadPseudoFields set to true.

In _getRecords_addPseudoFields() it will call getListOptionsFromSchema() with $selectedValues as an empty array.

This runs a query on table B with no WHERE clause, so it pulls the first 1000 rows from the table which can take a few seconds to run on a large table.

But there's no need to populate the label on a null value, so the whole thing doesn't even need to be run.

So what I've done is edit line 602+ as such:

elseif (!empty($selectedValues)) {
  $listOptions    = getListOptionsFromSchema($fieldSchema, null, false, $selectedValues);
  $values         = array_pluck($listOptions, '0');
  $labels         = array_pluck($listOptions, '1');
  $valuesToLabels = $listOptions ? array_combine($values, $labels) : [];
}
else {
  continue;
}