Skip StatementCache for eager loaded associations (Fixes #16761)

Eagerly loaded collection and singular associations are ignored by the StatementCache, which causes errors when the queries they generate reference columns that were not eagerly loaded.

This commit skips the creation of the StatementCache as a fix for these scenarios.

2 files changed, 11 insertions, 0 deletions

diff --git a/activerecord/test/models/comment.rb b/activerecord/test/models/comment.rb
index 7a88299d08..b38b17e90e 100644
--- a/activerecord/test/models/comment.rb
+++ b/activerecord/test/models/comment.rb
@@ -52,3 +52,8 @@ class CommentThatAutomaticallyAltersPostBody < Comment
     comment.post.update_attributes(body: "Automatically altered")
   end
 end
+
+class CommentWithDefaultScopeReferencesAssociation < Comment
+  default_scope ->{ includes(:developer).order('developers.name').references(:developer) }
+  belongs_to :developer
+end
diff --git a/activerecord/test/models/post.rb b/activerecord/test/models/post.rb
index 56a31011da..256b720c9a 100644
--- a/activerecord/test/models/post.rb
+++ b/activerecord/test/models/post.rb
@@ -218,3 +218,9 @@ class PostThatLoadsCommentsInAnAfterSaveHook < ActiveRecord::Base
     post.comments.load
   end
 end
+
+class PostWithCommentWithDefaultScopeReferencesAssociation < ActiveRecord::Base
+  self.table_name = 'posts'
+  has_many :comment_with_default_scope_references_associations, foreign_key: :post_id
+  has_one :first_comment, class_name: "CommentWithDefaultScopeReferencesAssociation", foreign_key: :post_id
+end