CollectionProxy uses the arel of its association's scope.

CollectionProxy should be able to reuse the behavior (methods) of its parent class,
but with its own state. This change allows CollectionProxy to use the arel object
corresponding to its association's scope.

4 files changed, 23 insertions, 0 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 1aeba4f856..d31551d606 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,12 @@
+*   `to_sql` on an association now matches the query that is actually executed, where it
+    could previously have incorrectly accrued additional conditions (e.g. as a result of
+    a previous query). CollectionProxy now always defers to the association scope's
+    `arel` method so the (incorrect) inherited one should be entirely concealed.
+
+    Fixes #14003.
+
+    *Jefferson Lai*
+
 *   The PostgreSQL adapter supports custom domains. Fixes #14305.
 
     *Yves Senn*
diff --git a/activerecord/lib/active_record/associations/collection_proxy.rb b/activerecord/lib/active_record/associations/collection_proxy.rb
index eba688866c..5b71ed163e 100644
--- a/activerecord/lib/active_record/associations/collection_proxy.rb
+++ b/activerecord/lib/active_record/associations/collection_proxy.rb
@@ -860,6 +860,10 @@ module ActiveRecord
         !!@association.include?(record)
       end
 
+      def arel
+        scope.arel
+      end
+
       def proxy_association
         @association
       end
diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index fddb7c204a..049c5a0606 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -573,6 +573,12 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal expected, actual
   end
 
+  def test_to_sql_on_scoped_proxy
+    auth = Author.first
+    Post.where("1=1").written_by(auth)
+    assert_not auth.posts.to_sql.include?("1=1")
+  end
+
   def test_loading_with_one_association_with_non_preload
     posts = Post.eager_load(:last_comment).order('comments.id DESC')
     post = posts.find { |p| p.id == 1 }
diff --git a/activerecord/test/models/post.rb b/activerecord/test/models/post.rb
index faf539a562..099e039255 100644
--- a/activerecord/test/models/post.rb
+++ b/activerecord/test/models/post.rb
@@ -149,6 +149,10 @@ class Post < ActiveRecord::Base
     ranked_by_comments.limit_by(limit)
   end
 
+  def self.written_by(author)
+    where(id: author.posts.pluck(:id))
+  end
+
   def self.reset_log
     @log = []
   end