4 files changed, 17 insertions, 11 deletions
diff --git a/actionview/lib/action_view/template/error.rb b/actionview/lib/action_view/template/error.rb
index 7b4b5e13e0..743ef6de0a 100644
--- a/actionview/lib/action_view/template/error.rb
+++ b/actionview/lib/action_view/template/error.rb
@@ -41,6 +41,9 @@ module ActionView
         'template'
       end
 
+      if partial && path.present?
+        path = path.sub(%r{([^/]+)$}, "_\\1")
+      end
       searched_paths = prefixes.map { |prefix| [prefix, path].join("/") }
 
       out  = "Missing #{template_type} #{searched_paths.join(", ")} with #{details.inspect}. Searched in:\n"
diff --git a/actionview/lib/action_view/template/handlers/erb.rb b/actionview/lib/action_view/template/handlers/erb.rb
index c8a0059596..4523060442 100644
--- a/actionview/lib/action_view/template/handlers/erb.rb
+++ b/actionview/lib/action_view/template/handlers/erb.rb
@@ -18,7 +18,7 @@ module ActionView
             src << "@output_buffer.safe_append='"
             src << "\n" * @newline_pending if @newline_pending > 0
             src << escape_text(text)
-            src << "';"
+            src << "'.freeze;"
 
             @newline_pending = 0
           end
@@ -67,7 +67,7 @@ module ActionView
 
         def flush_newline_if_pending(src)
           if @newline_pending > 0
-            src << "@output_buffer.safe_append='#{"\n" * @newline_pending}';"
+            src << "@output_buffer.safe_append='#{"\n" * @newline_pending}'.freeze;"
             @newline_pending = 0
           end
         end
diff --git a/actionview/lib/action_view/template/resolver.rb b/actionview/lib/action_view/template/resolver.rb
index 3304605c1a..3a3b74cdd5 100644
--- a/actionview/lib/action_view/template/resolver.rb
+++ b/actionview/lib/action_view/template/resolver.rb
@@ -1,6 +1,6 @@
 require "pathname"
 require "active_support/core_ext/class"
-require "active_support/core_ext/class/attribute_accessors"
+require "active_support/core_ext/module/attribute_accessors"
 require "action_view/template"
 require "thread"
 require "thread_safe"
@@ -162,8 +162,8 @@ module ActionView
 
   # An abstract class that implements a Resolver with path semantics.
   class PathResolver < Resolver #:nodoc:
-    EXTENSIONS = [:locale, :formats, :handlers]
-    DEFAULT_PATTERN = ":prefix/:action{.:locale,}{.:formats,}{.:handlers,}"
+    EXTENSIONS = { :locale => ".", :formats => ".", :variants => "+", :handlers => "." }
+    DEFAULT_PATTERN = ":prefix/:action{.:locale,}{.:formats,}{+:variants,}{.:handlers,}"
 
     def initialize(pattern=nil)
       @pattern = pattern || DEFAULT_PATTERN
@@ -240,7 +240,9 @@ module ActionView
       end
 
       handler = Template.handler_for_extension(extension)
-      format  = pieces.last && Template::Types[pieces.last]
+      format  = pieces.last && pieces.last.split(EXTENSIONS[:variants], 2).first # remove variant from format
+      format  &&= Template::Types[format]
+
       [handler, format]
     end
   end
@@ -303,12 +305,13 @@ module ActionView
   # An Optimized resolver for Rails' most common case.
   class OptimizedFileSystemResolver < FileSystemResolver #:nodoc:
     def build_query(path, details)
-      exts = EXTENSIONS.map { |ext| details[ext] }
       query = escape_entry(File.join(@path, path))
 
-      query + exts.map { |ext|
-        "{#{ext.compact.uniq.map { |e| ".#{e}," }.join}}"
-      }.join
+      exts = EXTENSIONS.map do |ext, prefix|
+        "{#{details[ext].compact.uniq.map { |e| "#{prefix}#{e}," }.join}}"
+      end.join
+
+      query + exts
     end
   end
 
diff --git a/actionview/lib/action_view/template/types.rb b/actionview/lib/action_view/template/types.rb
index db77cb5d19..b84e0281ae 100644
--- a/actionview/lib/action_view/template/types.rb
+++ b/actionview/lib/action_view/template/types.rb
@@ -1,5 +1,5 @@
 require 'set'
-require 'active_support/core_ext/class/attribute_accessors'
+require 'active_support/core_ext/module/attribute_accessors'
 
 module ActionView
   class Template