CollectionProxy#pluck issues no query for a new_record? owner

Fixes #8102.

I couldn't find a nicer way to deal with this than delegate the call to
 #scope, which will be a NullRelation when we want it to be.

2 files changed, 5 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/associations/collection_proxy.rb b/activerecord/lib/active_record/associations/collection_proxy.rb
index 50f9fca7c0..e044099b72 100644
--- a/activerecord/lib/active_record/associations/collection_proxy.rb
+++ b/activerecord/lib/active_record/associations/collection_proxy.rb
@@ -965,6 +965,10 @@ module ActiveRecord
         proxy_association.reload
         self
       end
+
+      def pluck(column_names)
+        scope.pluck(column_names)
+      end
     end
   end
 end
diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index 6355094a79..baf07f352e 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -1655,6 +1655,7 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     assert_no_queries do
       assert_equal [], post.comments
       assert_equal [], post.comments.where(body: 'omg')
+      assert_equal [], post.comments.pluck(:body)
     end
   end
 end