1 files changed, 42 insertions, 11 deletions
diff --git a/actionpack/lib/abstract_controller/layouts.rb b/actionpack/lib/abstract_controller/layouts.rb
index 796ef40584..c71cef42b2 100644
--- a/actionpack/lib/abstract_controller/layouts.rb
+++ b/actionpack/lib/abstract_controller/layouts.rb
@@ -89,7 +89,7 @@ module AbstractController
       # ==== Returns
       # String:: A template name
       def _implied_layout_name
-        name.underscore
+        name && name.underscore
       end
 
       # Takes the specified layout and creates a _layout method to be called
@@ -100,7 +100,7 @@ module AbstractController
       # name, return that string. Otherwise, use the superclass'
       # layout (which might also be implied)
       def _write_layout_method
-        case @_layout
+        case defined?(@_layout) ? @_layout : nil
         when String
           self.class_eval %{def _layout(details) #{@_layout.inspect} end}
         when Symbol
@@ -119,17 +119,19 @@ module AbstractController
         when true
           raise ArgumentError, "Layouts must be specified as a String, Symbol, false, or nil"
         when nil
-          self.class_eval <<-RUBY, __FILE__, __LINE__ + 1
-            def _layout(details)
-              self.class.cache_layout(details) do
-                if template_exists?("#{_implied_layout_name}", details, :_prefix => "layouts")
-                  "#{_implied_layout_name}"
-                else
-                  super
+          if name
+            self.class_eval <<-RUBY, __FILE__, __LINE__ + 1
+              def _layout(details)
+                self.class.cache_layout(details) do
+                  if template_exists?("#{_implied_layout_name}", details, :_prefix => "layouts")
+                    "#{_implied_layout_name}"
+                  else
+                    super
+                  end
                 end
               end
-            end
-          RUBY
+            RUBY
+          end
         end
         self.class_eval { private :_layout }
       end
@@ -157,6 +159,7 @@ module AbstractController
     end
 
   private
+
     # This will be overwritten by _write_layout_method
     def _layout(details) end
 
@@ -171,6 +174,34 @@ module AbstractController
       name && _find_layout(name, details)
     end
 
+    # Determine the layout for a given name and details, taking into account
+    # the name type.
+    #
+    # ==== Parameters
+    # name<String|TrueClass|FalseClass|Symbol>:: The name of the template
+    # details<Hash{Symbol => Object}>:: A list of details to restrict
+    #   the lookup to. By default, layout lookup is limited to the
+    #   formats specified for the current request.
+    def _layout_for_option(name, details)
+      case name
+      when String     then _layout_for_name(name, details)
+      when true       then _default_layout(details, true)
+      when :default   then _default_layout(details, false)
+      when false, nil then nil
+      else
+        raise ArgumentError,
+          "String, true, or false, expected for `layout'; you passed #{name.inspect}"
+      end
+    end
+
+    def _determine_template(options)
+      super
+
+      return unless (options.keys & [:text, :inline, :partial]).empty? || options.key?(:layout)
+      layout = options.key?(:layout) ? options[:layout] : :default
+      options[:_layout] = _layout_for_option(layout, options[:_template].details)
+    end
+
     # Take in the name and details and find a Template.
     #
     # ==== Parameters