From 307225eafb096f2afcb877a872e13289b40ac879 Mon Sep 17 00:00:00 2001
From: Andrew White <andyw@pixeltrix.co.uk>
Date: Wed, 31 Mar 2010 03:12:10 +0100
Subject: [PATCH] Refactor compute_type to handle situations where the correct class is already loaded

---
 activerecord/lib/active_record/base.rb  |   35 ++++++++++++++++--------------
 activerecord/test/cases/base_test.rb    |    5 ----
 activerecord/test/cases/modules_test.rb |    8 +++++++
 3 files changed, 27 insertions(+), 21 deletions(-)

diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 3aab5c0..af6fd56 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -1690,16 +1690,6 @@ module ActiveRecord #:nodoc:
           object
         end
 
-        # Nest the type name in the same module as this class.
-        # Bar is "MyApp::Business::Bar" relative to MyApp::Business::Foo
-        def type_name_with_module(type_name)
-          if store_full_sti_class
-            type_name
-          else
-            (/^::/ =~ type_name) ? type_name : "#{parent.name}::#{type_name}"
-          end
-        end
-
         def default_select(qualified)
           if qualified
             quoted_table_name + '.*'
@@ -2221,13 +2211,26 @@ module ActiveRecord #:nodoc:
         # Returns the class type of the record using the current module as a prefix. So descendants of
         # MyApp::Business::Account would appear as MyApp::Business::AccountSubclass.
         def compute_type(type_name)
-          modularized_name = type_name_with_module(type_name)
-          silence_warnings do
-            begin
-              class_eval(modularized_name, __FILE__, __LINE__)
-            rescue NameError
-              class_eval(type_name, __FILE__, __LINE__)
+          if type_name.match(/^::/)
+            # If the type is prefixed with a scope operator then we assume that
+            # the type_name is an absolute reference.
+            type_name.constantize
+          else
+            # Build a list of candidates to search for
+            candidates = []
+            name.scan(/::|$/) { candidates.unshift "#{$`}::#{type_name}" }
+            candidates << type_name
+
+            candidates.each do |candidate|
+              begin
+                constant = candidate.constantize
+                return constant if candidate == constant.to_s
+              rescue NameError
+              rescue ArgumentError
+              end
             end
+
+            raise NameError, "uninitialized constant #{candidates.first}"
           end
         end
 
diff --git a/activerecord/test/cases/base_test.rb b/activerecord/test/cases/base_test.rb
index 2bf7939..d71befb 100755
--- a/activerecord/test/cases/base_test.rb
+++ b/activerecord/test/cases/base_test.rb
@@ -2073,11 +2073,6 @@ class BasicsTest < ActiveRecord::TestCase
     assert xml.include?(%(<arbitrary-element>#{value}</arbitrary-element>))
   end
 
-  def test_type_name_with_module_should_handle_beginning
-    assert_equal 'ActiveRecord::Person', ActiveRecord::Base.send(:type_name_with_module, 'Person')
-    assert_equal '::Person', ActiveRecord::Base.send(:type_name_with_module, '::Person')
-  end
-
   def test_to_param_should_return_string
     assert_kind_of String, Client.find(:first).to_param
   end
diff --git a/activerecord/test/cases/modules_test.rb b/activerecord/test/cases/modules_test.rb
index 62d5401..a90ab81 100644
--- a/activerecord/test/cases/modules_test.rb
+++ b/activerecord/test/cases/modules_test.rb
@@ -106,4 +106,12 @@ class ModulesTest < ActiveRecord::TestCase
     ActiveRecord::Base.table_name_prefix = ''
     classes.each(&:reset_table_name)
   end
+
+  def test_compute_type_can_infer_class_name_of_sibling_inside_module
+    old = ActiveRecord::Base.store_full_sti_class
+    ActiveRecord::Base.store_full_sti_class = true
+    assert_equal MyApplication::Business::Firm, MyApplication::Business::Client.send(:compute_type, "Firm")
+  ensure
+    ActiveRecord::Base.store_full_sti_class = old
+  end
 end
-- 
1.6.4.4