4 files changed, 23 insertions, 0 deletions
diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 98fe0fbd62..fff66f21fb 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*
+
 *   Block a few default Class methods as scope name.
 
     For instance, this will raise:
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