Apply anonymous blocks without an owner as global

lib/use_case/question/create.rb

@@ -72,7 +72,7 @@ module UseCase
 
       def filtered?(question)
         target_user.mute_rules.any? { |rule| rule.applies_to? question } ||
-          (anonymous && target_user.anonymous_blocks.where(identifier: question.author_identifier).any?)
+          (anonymous && AnonymousBlock.where(identifier: question.author_identifier, user_id: [target_user.id, nil]).any?)
       end
 
       def source_user

spec/lib/use_case/question/create_spec.rb

@@ -79,6 +79,18 @@ describe UseCase::Question::Create do
 
       it_behaves_like "creates the question", false
     end
+
+    context "question is from an anon who is blocked globally" do
+      before do
+        AnonymousBlock.create!(
+          identifier:  author_identifier,
+          question_id: FactoryBot.create(:question).id,
+          user_id:     nil
+        )
+      end
+
+      it_behaves_like "creates the question", false
+    end
   end
 
   context "user signed in" do