Chain scope constraints should respect own table alias

Fixes #27666.

activerecord/lib/active_record/associations/association_scope.rb

@@ -128,9 +128,9 @@ module ActiveRecord
           reflection = chain_head
           while reflection
             table = reflection.alias_name
+            next_reflection = reflection.next
 
             unless reflection == chain_tail
-              next_reflection = reflection.next
               foreign_table = next_reflection.alias_name
               scope = next_chain_scope(scope, table, reflection, association_klass, foreign_table, next_reflection)
             end
@@ -138,7 +138,7 @@ module ActiveRecord
             # Exclude the scope of the association itself, because that
             # was already merged in the #scope method.
             reflection.constraints.each do |scope_chain_item|
-              item  = eval_scope(reflection.klass, scope_chain_item, owner)
+              item = eval_scope(reflection.klass, table, scope_chain_item, owner)
 
               if scope_chain_item == refl.scope
                 scope.merge! item.except(:where, :includes)
@@ -153,14 +153,15 @@ module ActiveRecord
               scope.order_values |= item.order_values
             end
 
-            reflection = reflection.next
+            reflection = next_reflection
           end
 
           scope
         end
 
-        def eval_scope(klass, scope, owner)
-          klass.unscoped.instance_exec(owner, &scope)
+        def eval_scope(klass, table, scope, owner)
+          predicate_builder = PredicateBuilder.new(TableMetadata.new(klass, table))
+          ActiveRecord::Relation.create(klass, table, predicate_builder).instance_exec(owner, &scope)
         end
     end
   end

activerecord/test/cases/associations/has_many_through_associations_test.rb

@@ -28,6 +28,9 @@ require "models/member"
 require "models/membership"
 require "models/club"
 require "models/organization"
+require "models/user"
+require "models/family"
+require "models/family_tree"
 
 class HasManyThroughAssociationsTest < ActiveRecord::TestCase
   fixtures :posts, :readers, :people, :comments, :authors, :categories, :taggings, :tags,
@@ -1232,6 +1235,17 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
     TenantMembership.current_member = nil
   end
 
+  def test_has_many_through_with_scope_should_respect_table_alias
+    family = Family.create!
+    users = 3.times.map { User.create! }
+    FamilyTree.create!(member: users[0], family: family)
+    FamilyTree.create!(member: users[1], family: family)
+    FamilyTree.create!(member: users[2], family: family, token: "wat")
+
+    assert_equal 2, users[0].family_members.to_a.size
+    assert_equal 0, users[2].family_members.to_a.size
+  end
+
   def test_incorrectly_ordered_through_associations
     assert_raises(ActiveRecord::HasManyThroughOrderError) do
       DeveloperWithIncorrectlyOrderedHasManyThrough.create(

activerecord/test/models/family.rb

@@ -0,0 +1,4 @@
+class Family < ActiveRecord::Base
+  has_many :family_trees, -> { where(token: nil) }
+  has_many :members, through: :family_trees
+end

activerecord/test/models/family_tree.rb

@@ -0,0 +1,4 @@
+class FamilyTree < ActiveRecord::Base
+  belongs_to :member, class_name: "User", foreign_key: "member_id"
+  belongs_to :family
+end

activerecord/test/models/user.rb

@@ -7,6 +7,10 @@ class User < ActiveRecord::Base
   has_and_belongs_to_many :jobs_pool,
     class_name: "Job",
     join_table: "jobs_pool"
+
+  has_one :family_tree, -> { where(token: nil) }, foreign_key: "member_id"
+  has_one :family, through: :family_tree
+  has_many :family_members, through: :family, source: :members
 end
 
 class UserWithNotification < User

activerecord/test/schema/schema.rb

@@ -329,6 +329,15 @@ ActiveRecord::Schema.define do
   create_table :eyes, force: true do |t|
   end
 
+  create_table :families, force: true do |t|
+  end
+
+  create_table :family_trees, force: true do |t|
+    t.references :family
+    t.references :member
+    t.string :token
+  end
+
   create_table :funny_jokes, force: true do |t|
     t.string :name
   end