Fixes #3148 - Knowledge Base search crashes if (parent) category is missing translation to the locale of the found object

app/controllers/knowledge_base/search_controller.rb

@@ -1,6 +1,6 @@
 class KnowledgeBase::SearchController < ApplicationController
   skip_before_action :verify_csrf_token
-  #skip_before_action :verify_authenticity_token
+  prepend_before_action :authentication_check_only
 
   include KnowledgeBaseHelper
   include ActionView::Helpers::SanitizeHelper
@@ -74,7 +74,7 @@ class KnowledgeBase::SearchController < ApplicationController
   end
 
   def public_item_details_answer(meta, object)
-    category_translation = object.answer.category.translation_to(object.kb_locale)
+    category_translation = object.answer.category.translation_preferred(object.kb_locale)
     path = help_answer_path(category_translation, object, locale: object.kb_locale.system_locale.locale)
 
     url = case url_type
@@ -97,7 +97,7 @@ class KnowledgeBase::SearchController < ApplicationController
   end
 
   def public_item_details_category(meta, object)
-    parent_category_translation = object.category.parent&.translation_to(object.kb_locale)
+    parent_category_translation = object.category.parent&.translation_preferred(object.kb_locale)
     path = help_category_path(object, locale: object.kb_locale.system_locale.locale)
 
     url = case url_type

spec/requests/knowledge_base/search_with_details_spec.rb

@@ -30,4 +30,35 @@ RSpec.describe 'Knowledge Base search with details', type: :request, searchindex
       expect(json_response['details'][0]['id']).to be_a_kind_of Integer
     end
   end
+
+  context 'when category translation to one of locales is missing' do
+    let(:search_phrase) { 'search_phrase' }
+    let(:alternative_translation) { create('knowledge_base/answer/translation', title: search_phrase, kb_locale: alternative_locale, answer: published_answer) }
+
+    before do
+      alternative_translation
+      rebuild_searchindex
+    end
+
+    it 'returns answer in locale without category translation' do
+      post endpoint, params: { query: search_phrase }
+
+      expect(json_response['details'][0]['id']).to be alternative_translation.id
+    end
+  end
+
+  context 'when parent category translation to one of locales is missing' do
+    let(:search_phrase)  { 'search_phrase' }
+    let(:child_category) { create('knowledge_base/category', parent: category) }
+    let(:child_category_translation) { create('knowledge_base/category/translation', title: search_phrase, kb_locale: alternative_locale, category: child_category) }
+
+    before do
+      child_category_translation && rebuild_searchindex
+    end
+
+    it 'returns category in locale without category translation', authenticated_as: -> { create(:admin) } do
+      post endpoint, params: { query: search_phrase }
+      expect(json_response['details'][0]['subtitle']).to eq category.translation_to(primary_locale).title
+    end
+  end
 end