Maintenance: Improve translation search collector to handle nil descriptions

Approved-by: Florian Liebe <fl@zammad.com>

app/services/service/translation/search/collector/public_link.rb

@@ -20,6 +20,6 @@ class Service::Translation::Search::Collector::PublicLink < Service::Translation
   end
 
   def link_descriptions
-    public_links.pluck(:description)
+    public_links.pluck(:description).compact
   end
 end

spec/services/service/translation/search_spec.rb

@@ -85,6 +85,17 @@ RSpec.describe Service::Translation::Search do
           context 'with description attribute' do
             it_behaves_like 'returns filtered result', :public_link, 'description', 2
           end
+
+          context 'with nil description on a public link' do
+            before do
+              create(:public_link, description: nil)
+              create(:public_link, description: "desc #{query}")
+            end
+
+            it 'does not crash on nil descriptions' do
+              expect { service_result }.not_to raise_error
+            end
+          end
         end
 
         context 'with custom object attribute' do