Bug 22222: Don't send empty params to mana service

Test plan:
0) Do not apply the patch
1) Go to serials > Search on Mana
2) Insert some value into the form
3) Submit -> you get many (3000+) results
4) Apply the patch and restart_all
5) Repeat, now, you get only the subscription matching your query

Signed-off-by: Michal Denar <black23@gmail.com>
Signed-off-by: Alex Arnaud <alex.arnaud@biblibre.com>

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>

Koha/SharedContent.pm

@@ -154,7 +154,7 @@ sub build_request {
     if ( $type eq 'get' ) {
         my $params = shift;
         $params = join '&',
-            map { defined $params->{$_} ? $_ . "=" . $params->{$_} : () }
+            map { defined $params->{$_} && $params->{$_} ne '' ? $_ . "=" . $params->{$_} : () }
             keys %$params;
         my $url = "$mana_url/$resource.json?$params";
         return HTTP::Request->new( GET => $url );
@@ -164,7 +164,7 @@ sub build_request {
         my $id = shift;
         my $params = shift;
         $params = join '&',
-            map { defined $params->{$_} ? $_ . "=" . $params->{$_} : () }
+            map { defined $params->{$_} && $params->{$_} ne '' ? $_ . "=" . $params->{$_} : () }
             keys %$params;
 
         my $url = "$mana_url/$resource/$id.json?$params";

t/db_dependent/Koha/SharedContent.t

@@ -82,7 +82,7 @@ is($request->method, 'GET', 'Get subscription - Method is get');
 my %query = $request->uri->query_form;
 is($query{title}, 'The English historical review', 'Check title');
 is($query{issn}, '0013-8266', 'Check issn');
-is($query{ean}, '', 'Check ean');
+is($query{ean}, undef, 'Check ean');
 is($query{publishercode}, 'Longman', 'Check publisher');
 
 is($request->uri->path, '/subscription.json', 'Path is subscription');