Ensures a nil location is not processed when enumerating usernames

lib/common/models/wp_user/existable.rb

@@ -22,6 +22,8 @@ class WpUser < WpItem
       if response.code == 301 # login in location?
         location = response.headers_hash['Location']
 
+        return unless location
+
         @login        = Existable.login_from_author_pattern(location)
         @display_name = Existable.display_name_from_body(
           Browser.get(location).body

spec/shared_examples/wp_user/existable.rb

@@ -124,6 +124,15 @@ shared_examples 'WpUser::Existable' do
         @login        = 'admin'
         @display_name = 'admin name'
       end
+
+      context 'when the location is nil' do
+        let(:location) { nil }
+
+        it 'returns nil' do
+          @login        = nil
+          @display_name = nil
+        end
+      end
     end
 
     context 'with a 200' do