6 files changed, 19 insertions, 1 deletions
diff --git a/actionpack/lib/action_controller/metal/responder.rb b/actionpack/lib/action_controller/metal/responder.rb
index 4ad64bff20..daa1ddd65f 100644
--- a/actionpack/lib/action_controller/metal/responder.rb
+++ b/actionpack/lib/action_controller/metal/responder.rb
@@ -267,7 +267,7 @@ module ActionController #:nodoc:
     end
 
     def resource_errors
-      respond_to?("#{format}_resource_errors") ? send("#{format}_resource_errors") : resource.errors
+      respond_to?("#{format}_resource_errors", true) ? send("#{format}_resource_errors") : resource.errors
     end
 
     def json_resource_errors
diff --git a/actionpack/lib/action_view/template.rb b/actionpack/lib/action_view/template.rb
index edb3d427d5..644debd49c 100644
--- a/actionpack/lib/action_view/template.rb
+++ b/actionpack/lib/action_view/template.rb
@@ -163,6 +163,7 @@ module ActionView
       pieces  = @virtual_path.split("/")
       name    = pieces.pop
       partial = !!name.sub!(/^_/, "")
+      lookup.formats = @formats
       lookup.disable_cache do
         lookup.find_template(name, [ pieces.join('/') ], partial, @locals)
       end
diff --git a/actionpack/lib/action_view/template/handlers.rb b/actionpack/lib/action_view/template/handlers.rb
index 67978ada7e..4e22bec6cc 100644
--- a/actionpack/lib/action_view/template/handlers.rb
+++ b/actionpack/lib/action_view/template/handlers.rb
@@ -23,6 +23,7 @@ module ActionView #:nodoc:
       # and should return the rendered template as a String.
       def register_template_handler(extension, handler)
         @@template_handlers[extension.to_sym] = handler
+        @@template_extensions = nil
       end
 
       def template_handler_extensions
diff --git a/actionpack/test/fixtures/with_format.json.erb b/actionpack/test/fixtures/with_format.json.erb
new file mode 100644
index 0000000000..a7f480ab1d
--- /dev/null
+++ b/actionpack/test/fixtures/with_format.json.erb
@@ -0,0 +1 @@
+<%= render :partial => 'missing', :formats => [:json] %>
diff --git a/actionpack/test/template/render_test.rb b/actionpack/test/template/render_test.rb
index 5d3dc73ed2..e4ce756bf8 100644
--- a/actionpack/test/template/render_test.rb
+++ b/actionpack/test/template/render_test.rb
@@ -51,6 +51,13 @@ module RenderTestCases
     assert_match "<error>No Comment</error>", @view.render(:template => "comments/empty", :formats => [:xml])
   end
 
+  def test_render_template_with_a_missing_partial_of_another_format
+    assert_raise ActionView::Template::Error, "Missing partial /missing with {:locale=>[:en], :formats=>[:json], :handlers=>[:erb, :builder]}" do
+      @view.lookup_context.freeze_formats([:html])
+      @view.render(:template => "with_format", :formats => [:json])
+    end
+  end
+
   def test_render_file_with_locale
     assert_equal "<h1>Kein Kommentar</h1>", @view.render(:file => "comments/empty", :locale => [:de])
     assert_equal "<h1>Kein Kommentar</h1>", @view.render(:file => "comments/empty", :locale => :de)
@@ -299,6 +306,12 @@ module RenderTestCases
     ActionView::Template.register_template_handler :foo, CustomHandler
     assert_equal 'source: "Hello, <%= name %>!"', @view.render(:inline => "Hello, <%= name %>!", :locals => { :name => "Josh" }, :type => :foo)
   end
+  
+  def test_render_knows_about_types_registered_when_extensions_are_checked_earlier_in_initialization
+    ActionView::Template::Handlers.extensions
+    ActionView::Template.register_template_handler :foo, CustomHandler
+    assert ActionView::Template::Handlers.extensions.include?(:foo)
+  end
 
   def test_render_ignores_templates_with_malformed_template_handlers
     ActiveSupport::Deprecation.silence do
diff --git a/actionpack/test/template/template_test.rb b/actionpack/test/template/template_test.rb
index 3084527f70..63f1d3a6c0 100644
--- a/actionpack/test/template/template_test.rb
+++ b/actionpack/test/template/template_test.rb
@@ -11,6 +11,8 @@ class TestERBTemplate < ActiveSupport::TestCase
 
     def find_template(*args)
     end
+
+    attr_writer :formats
   end
 
   class Context