render :template => 'foo/bar.json' now works as it should.

1 files changed, 18 insertions, 3 deletions

diff --git a/actionpack/lib/action_view/render/rendering.rb b/actionpack/lib/action_view/render/rendering.rb
index 0771b40c37..8e599c71df 100644
--- a/actionpack/lib/action_view/render/rendering.rb
+++ b/actionpack/lib/action_view/render/rendering.rb
@@ -21,9 +21,11 @@ module ActionView
         elsif options.key?(:partial)
           _render_partial(options)
         else
-          template = _determine_template(options)
-          lookup_context.freeze_formats(template.formats, true)
-          _render_template(template, options[:layout], options)
+          _wrap_formats(options[:template] || options[:file]) do
+            template = _determine_template(options)
+            lookup_context.freeze_formats(template.formats, true)
+            _render_template(template, options[:layout], options)
+          end
         end
       when :update
         update_page(&block)
@@ -32,6 +34,19 @@ module ActionView
       end
     end
 
+    # Checks if the given path contains a format and if so, change
+    # the lookup context to take this new format into account.
+    def _wrap_formats(value)
+      return yield unless value.is_a?(String)
+      @@formats_regexp ||= /\.(#{Mime::SET.symbols.join('|')})$/
+
+      if value.sub!(@@formats_regexp, "")
+        update_details(:formats => [$1.to_sym]){ yield }
+      else
+        yield
+      end
+    end
+
     # Determine the template to be rendered using the given options.
     def _determine_template(options) #:nodoc:
       keys = (options[:locals] ||= {}).keys