Specify the STI type condition using SQL IN rather than a whole load …

…of ORs. Required a fix to ActiveRecord::Relation#merge for properly merging create_with_value. This also fixes a situation where the type condition was appearing twice in the resultant SQL query.

activerecord/lib/active_record/associations/association_collection.rb

@@ -488,7 +488,7 @@ def create_record(attrs, &block)
           ensure_owner_is_persisted!
 
           transaction do
-            with_scope(:create => @scope[:create].merge(scoped.where_values_hash)) do
+            with_scope(:create => @scope[:create].merge(scoped.scope_for_create)) do
               build_record(attrs, &block)
             end
           end

activerecord/lib/active_record/base.rb

@@ -874,7 +874,12 @@ def before_remove_const #:nodoc:
 
         def relation #:nodoc:
           @relation ||= Relation.new(self, arel_table)
-          finder_needs_type_condition? ? @relation.where(type_condition) : @relation
+
+          if finder_needs_type_condition?
+            @relation.where(type_condition).create_with(inheritance_column.to_sym => sti_name)
+          else
+            @relation
+          end
         end
 
         # Finder methods must instantiate through this method to work with the
@@ -914,10 +919,9 @@ def construct_finder_arel(options = {}, scope = nil)
 
         def type_condition
           sti_column = arel_table[inheritance_column.to_sym]
-          condition = sti_column.eq(sti_name)
-          descendants.each { |subclass| condition = condition.or(sti_column.eq(subclass.sti_name)) }
+          sti_names  = ([self] + descendants).map { |model| model.sti_name }
 
-          condition
+          sti_column.in(sti_names)
         end
 
         # Guesses the table name, but does not decorate it with prefix and suffix information.

activerecord/lib/active_record/relation/spawn_methods.rb

@@ -46,13 +46,17 @@ def merge(r)
 
       merged_relation.where_values = merged_wheres
 
-      (Relation::SINGLE_VALUE_METHODS - [:lock]).each do |method|
+      (Relation::SINGLE_VALUE_METHODS - [:lock, :create_with]).each do |method|
         value = r.send(:"#{method}_value")
         merged_relation.send(:"#{method}_value=", value) unless value.nil?
       end
 
       merged_relation.lock_value = r.lock_value unless merged_relation.lock_value
 
+      if r.create_with_value
+        merged_relation.create_with_value = (merged_relation.create_with_value || {}).merge(r.create_with_value)
+      end
+
       # Apply scope extension modules
       merged_relation.send :apply_modules, r.extensions
 

activerecord/test/cases/relation_scoping_test.rb

@@ -485,4 +485,11 @@ def test_scope_composed_by_limit_and_then_offset_is_equal_to_scope_composed_by_o
     posts_offset_limit = Post.offset(2).limit(3)
     assert_equal posts_limit_offset, posts_offset_limit
   end
+
+  def test_create_with_merge
+    aaron = (PoorDeveloperCalledJamis.create_with(:name => 'foo', :salary => 20) &
+             PoorDeveloperCalledJamis.create_with(:name => 'Aaron')).new
+    assert_equal 20, aaron.salary
+    assert_equal 'Aaron', aaron.name
+  end
 end