## supposed to be a hash of simple values, hashes of arrays could be implemented
$filter_input->{$field}=format_date_in_iso($filter_input->{$field})
if $columns->{$field}{Type}=~/date/ &&
- $filter_input->{$field} !~C4::Dates->regexp("iso");
+ ($filter_input->{$field} && $filter_input->{$field} !~C4::Dates->regexp("iso"));
my ($tmpkeys, $localvalues)=_Process_Operands($filter_input->{$field},"$tablename.$field",$searchtype,$columns);
if (@$tmpkeys){
push @values, @$localvalues;