Use bind values for joined tables in where statements

In practical terms, this allows serialized columns and tz aware columns
to be used in wheres that go through joins, where they previously would
not behave correctly. Internally, this removes 1/3 of the cases where we
rely on Arel to perform type casting for us.

There were two non-obvious changes required for this. `update_all` on
relation was merging its bind values with arel's in the wrong order.
Additionally, through associations were assuming there would be no bind
parameters in the preloader (presumably because the where would always
be part of a join)

[Melanie Gilman & Sean Griffin]

activerecord/CHANGELOG.md

+*   Queries now properly type cast values that are part of a join statement,
+    even when using type decorators such as `serialize`.
+
+    *Melanie Gilman & Sean Griffin*
+
 *   MySQL enum type lookups, with values matching another type, no longer result
     in an endless loop.
 

activerecord/lib/active_record/associations/preloader/through_association.rb

@@ -81,6 +81,7 @@ def through_scope
             unless reflection_scope.where_values.empty?
               scope.includes_values = Array(reflection_scope.values[:includes] || options[:source])
               scope.where_values    = reflection_scope.values[:where]
+              scope.bind_values     = reflection_scope.bind_values
             end
 
             scope.references! reflection_scope.values[:references]

activerecord/lib/active_record/relation.rb

@@ -336,7 +336,7 @@ def update_all(updates)
         stmt.wheres = arel.constraints
       end
 
-      bvs = bind_values + arel.bind_values
+      bvs = arel.bind_values + bind_values
       @klass.connection.update stmt, 'SQL', bvs
     end
 

activerecord/lib/active_record/relation/query_methods.rb

@@ -980,6 +980,10 @@ def create_binds(opts)
         end
       end
 
+      association_binds, non_binds = non_binds.partition do |column, value|
+        value.is_a?(Hash) && association_for_table(column)
+      end
+
       new_opts = {}
       binds = []
 
@@ -988,11 +992,24 @@ def create_binds(opts)
         new_opts[column] = connection.substitute_at(column)
       end
 
+      association_binds.each do |(column, value)|
+        association_relation = association_for_table(column).klass.send(:relation)
+        association_new_opts, association_bind = association_relation.send(:create_binds, value)
+        new_opts[column] = association_new_opts
+        binds += association_bind
+      end
+
       non_binds.each { |column,value| new_opts[column] = value }
 
       [new_opts, binds]
     end
 
+    def association_for_table(table_name)
+      table_name = table_name.to_s
+      @klass._reflect_on_association(table_name) ||
+        @klass._reflect_on_association(table_name.singularize)
+    end
+
     def build_from
       opts, name = from_value
       case opts

activerecord/test/cases/serialization_test.rb

@@ -2,6 +2,8 @@
 require 'models/contact'
 require 'models/topic'
 require 'models/book'
+require 'models/author'
+require 'models/post'
 
 class SerializationTest < ActiveRecord::TestCase
   fixtures :books
@@ -92,4 +94,11 @@ def test_read_attribute_for_serialization_with_format_after_find
     book = klazz.find(books(:awdr).id)
     assert_equal 'paperback', book.read_attribute_for_serialization(:format)
   end
+
+  def test_find_records_by_serialized_attributes_through_join
+    author = Author.create!(name: "David")
+    author.serialized_posts.create!(title: "Hello")
+
+    assert_equal 1, Author.joins(:serialized_posts).where(name: "David", serialized_posts: { title: "Hello" }).length
+  end
 end

activerecord/test/models/author.rb

 class Author < ActiveRecord::Base
   has_many :posts
+  has_many :serialized_posts
   has_one :post
   has_many :very_special_comments, :through => :posts
   has_many :posts_with_comments, -> { includes(:comments) }, :class_name => "Post"

activerecord/test/models/post.rb

@@ -233,3 +233,7 @@ class PostWithCommentWithDefaultScopeReferencesAssociation < ActiveRecord::Base
   has_many :comment_with_default_scope_references_associations, foreign_key: :post_id
   has_one :first_comment, class_name: "CommentWithDefaultScopeReferencesAssociation", foreign_key: :post_id
 end
+
+class SerializedPost < ActiveRecord::Base
+  serialize :title
+end

activerecord/test/schema/schema.rb

@@ -585,6 +585,11 @@ def except(adapter_names_to_exclude)
     t.integer :tags_with_nullify_count, default: 0
   end
 
+  create_table :serialized_posts, force: true do |t|
+    t.integer :author_id
+    t.string :title, null: false
+  end
+
   create_table :price_estimates, force: true do |t|
     t.string :estimate_of_type
     t.integer :estimate_of_id