Don't show out of stock products - search plugin

There is no option for that.
Please update the plugin with this package and deactivate the new "out of stock products" option and it will work like you want.

Then let's try that:
$out_of_stock = (int)$this->params->get('out_of_stock_display','1');

instead of:
$out_of_stock = $this->params->get('out_of_stock_display','1');

Mmmm. It's working fine on our end. Maybe it comes from joomfish. Do you use joomfish ?

If so, could you try to replace the line:
$query = ' SELECT DISTINCT '.$select.' FROM '.hikashop_table('jf_content',false) . ' AS b LEFT JOIN '.hikashop_table('product').' AS a ON b.reference_id=a.product_id WHERE '.implode(' AND ',$filters2).' ORDER BY '.$order;

by:
$filters2[]=implode(' AND ',$filters);
$query = ' SELECT DISTINCT '.$select.' FROM '.hikashop_table('jf_content',false) . ' AS b LEFT JOIN '.hikashop_table('product').' AS a ON b.reference_id=a.product_id WHERE '.implode(' AND ',$filters2).' ORDER BY '.$order;

There seems to be another problem when there are several fields selected for the search. Try to also replace the line:
$filters[] = '(' . implode( ') OR (', $wordFilters ) . ')';

to:
$filters[] = '((' . implode( ') OR (', $wordFilters ) . '))';

and the line:
$filters2[] = '(' . implode( ($phrase == 'all' ? ') AND (' : ') OR ('), $wordFilters2 ) . ')';
to:
$filters2[] = '((' . implode( ($phrase == 'all' ? ') AND (' : ') OR ('), $wordFilters2 ) . '))';