Fix const_missing to behave responsibly when called within anonymous modules

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4779 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activesupport/lib/active_support/dependencies.rb

@@ -65,7 +65,7 @@ def require_or_load(file_name, const_path = nil)
     # Record that we've seen this file *before* loading it to avoid an
     # infinite loop with mutual dependencies.
     loaded << expanded
-
+    
     if load?
       log "loading #{file_name}"
       begin
@@ -179,6 +179,11 @@ def qualified_name_for(mod, name)
   def load_missing_constant(from_mod, const_name)
     log_call from_mod, const_name
     
+    # If we have an anonymous module, all we can do is attempt to load from Object.
+    from_mod = Object if from_mod.name.empty?
+    
+    raise ArgumentError, "Expected #{from_mod} is not missing constant #{const_name}!" if from_mod.const_defined?(const_name)
+    
     qualified_name = qualified_name_for from_mod, const_name
     path_suffix = qualified_name.underscore
     name_error = NameError.new("uninitialized constant #{qualified_name}")

activesupport/test/dependencies_test.rb

@@ -346,10 +346,28 @@ module A
   end
   
   def test_const_missing_should_not_double_load
+    $counting_loaded_times = 0
     with_loading 'autoloading_fixtures' do
       require_dependency '././counting_loader'
       assert_equal 1, $counting_loaded_times
-      Dependencies.load_missing_constant Object, :CountingLoader
+      assert_raises(ArgumentError) { Dependencies.load_missing_constant Object, :CountingLoader }
+      assert_equal 1, $counting_loaded_times
+    end
+  end
+  
+  def test_const_missing_within_anonymous_module
+    $counting_loaded_times = 0
+    m = Module.new
+    m.module_eval "def a() CountingLoader; end"
+    extend m
+    kls = nil    
+    with_loading 'autoloading_fixtures' do
+      kls = nil
+      assert_nothing_raised { kls = a }
+      assert_equal "CountingLoader", kls.name
+      assert_equal 1, $counting_loaded_times
+      
+      assert_nothing_raised { kls = a }
       assert_equal 1, $counting_loaded_times
     end
   end