Fix polymorphic association subquery

activerecord/CHANGELOG.md

@@ -1,3 +1,19 @@
+*   Fix where on association with has_one/has_many polymorphic relations.
+
+    Before:
+    ```ruby
+    Treasure.where(price_estimates: PriceEstimate.all)
+    #=> SELECT (...) WHERE "treasures"."id" IN (SELECT "price_estimates"."estimate_of_id" FROM "price_estimates")
+    ```
+
+    Later:
+    ```ruby
+    Treasure.where(price_estimates: PriceEstimate.all)
+    #=> SELECT (...) WHERE "treasures"."id" IN (SELECT "price_estimates"."estimate_of_id" FROM "price_estimates" WHERE "price_estimates"."estimate_of_type" = 'Treasure')
+    ```
+
+    *Lázaro Nixon*
+
 *   Assign auto populated columns on Active Record record creation.
 
     Changes record creation logic to allow for the `auto_increment` column to be assigned

activerecord/lib/active_record/reflection.rb

@@ -531,6 +531,10 @@ def join_primary_key(klass = nil)
         foreign_key
       end
 
+      def join_primary_type
+        type
+      end
+
       def join_foreign_key
         active_record_primary_key
       end
@@ -634,6 +638,10 @@ def polymorphic?
         options[:polymorphic]
       end
 
+      def polymorphic_name
+        active_record.polymorphic_name
+      end
+
       def add_as_source(seed)
         seed
       end

activerecord/lib/active_record/relation/predicate_builder/association_query_value.rb

@@ -25,7 +25,10 @@ def queries
         def ids
           case value
           when Relation
-            value.select_values.empty? ? value.select(primary_key) : value
+            relation = value
+            relation = relation.select(primary_key) if select_clause?
+            relation = relation.where(primary_type => polymorphic_name) if polymorphic_clause?
+            relation
           when Array
             value.map { |v| convert_to_id(v) }
           else
@@ -37,6 +40,22 @@ def primary_key
           associated_table.join_primary_key
         end
 
+        def primary_type
+          associated_table.join_primary_type
+        end
+
+        def polymorphic_name
+          associated_table.polymorphic_name_association
+        end
+
+        def select_clause?
+          value.select_values.empty?
+        end
+
+        def polymorphic_clause?
+          primary_type && !value.where_values_hash.has_key?(primary_type)
+        end
+
         def convert_to_id(value)
           return primary_key.map { |pk| value.public_send(pk) } if primary_key.is_a?(Array)
 

activerecord/lib/active_record/table_metadata.rb

@@ -2,7 +2,7 @@
 
 module ActiveRecord
   class TableMetadata # :nodoc:
-    delegate :join_primary_key, :join_foreign_key, :join_foreign_type, to: :reflection
+    delegate :join_primary_key, :join_primary_type, :join_foreign_key, :join_foreign_type, to: :reflection
 
     def initialize(klass, arel_table, reflection = nil)
       @klass = klass
@@ -63,6 +63,10 @@ def polymorphic_association?
       reflection&.polymorphic?
     end
 
+    def polymorphic_name_association
+      reflection&.polymorphic_name
+    end
+
     def through_association?
       reflection&.through_reflection?
     end

activerecord/test/cases/relation/where_test.rb

@@ -458,6 +458,11 @@ def test_where_on_association_with_select_relation
       assert_equal essays(:david_modest_proposal), essay
     end
 
+    def test_where_on_association_with_collection_polymorphic_relation
+      treasures = Treasure.where(name: ["diamond", "emerald"], price_estimates: PriceEstimate.all)
+      assert_equal [treasures(:diamond)], treasures
+    end
+
     def test_where_with_strong_parameters
       author = authors(:david)
       params = ProtectedParams.new(name: author.name)

activerecord/test/fixtures/treasures.yml

@@ -8,3 +8,7 @@ sapphire:
 ruby:
   name: $LABEL
   looter: louis (Parrot)
+
+emerald:
+  id: 1
+  name: $LABEL