3 files changed, 55 insertions, 4 deletions
diff --git a/actionpack/lib/action_view/helpers/asset_tag_helper.rb b/actionpack/lib/action_view/helpers/asset_tag_helper.rb
index babb9db38a..14cdc7a025 100644
--- a/actionpack/lib/action_view/helpers/asset_tag_helper.rb
+++ b/actionpack/lib/action_view/helpers/asset_tag_helper.rb
@@ -1,6 +1,7 @@
 require 'cgi'
 require 'action_view/helpers/url_helper'
 require 'action_view/helpers/tag_helper'
+require 'active_support/core_ext/file'
 
 module ActionView
   module Helpers #:nodoc:
@@ -285,7 +286,7 @@ module ActionView
           end
           javascript_src_tag(joined_javascript_name, options)
         else
-          expand_javascript_sources(sources, recursive).collect { |source| javascript_src_tag(source, options) }.join("\n")
+          ensure_javascript_sources!(expand_javascript_sources(sources, recursive)).collect { |source| javascript_src_tag(source, options) }.join("\n")
         end
       end
 
@@ -434,7 +435,7 @@ module ActionView
           end
           stylesheet_tag(joined_stylesheet_name, options)
         else
-          expand_stylesheet_sources(sources, recursive).collect { |source| stylesheet_tag(source, options) }.join("\n")
+          ensure_stylesheet_sources!(expand_stylesheet_sources(sources, recursive)).collect { |source| stylesheet_tag(source, options) }.join("\n")
         end
       end
 
@@ -664,13 +665,28 @@ module ActionView
           end
         end
 
+        def ensure_stylesheet_sources!(sources)
+          sources.each do |source|
+            asset_file_path!(path_to_stylesheet(source))
+          end
+          return sources
+        end
+
+        def ensure_javascript_sources!(sources)
+          sources.each do |source|
+            asset_file_path!(path_to_javascript(source))
+          end
+          return sources
+        end
+
         def join_asset_file_contents(paths)
-          paths.collect { |path| File.read(asset_file_path(path)) }.join("\n\n")
+          paths.collect { |path| File.read(asset_file_path!(path)) }.join("\n\n")
         end
 
         def write_asset_file_contents(joined_asset_path, asset_paths)
+
           FileUtils.mkdir_p(File.dirname(joined_asset_path))
-          File.open(joined_asset_path, "w+") { |cache| cache.write(join_asset_file_contents(asset_paths)) }
+          File.atomic_write(joined_asset_path) { |cache| cache.write(join_asset_file_contents(asset_paths)) }
 
           # Set mtime to the latest of the combined files to allow for
           # consistent ETag without a shared filesystem.
@@ -682,6 +698,14 @@ module ActionView
           File.join(ASSETS_DIR, path.split('?').first)
         end
 
+        def asset_file_path!(path)
+          unless path =~ %r{^[-a-z]+://}
+            absolute_path = asset_file_path(path)
+            raise(Errno::ENOENT, "Asset file not found at '#{absolute_path}'" ) unless File.exist?(absolute_path)
+            return absolute_path
+          end
+        end
+
         def collect_asset_files(*path)
           dir = path.first
 
diff --git a/actionpack/lib/action_view/helpers/capture_helper.rb b/actionpack/lib/action_view/helpers/capture_helper.rb
index a8b5a9dbb9..c90acc5ac2 100644
--- a/actionpack/lib/action_view/helpers/capture_helper.rb
+++ b/actionpack/lib/action_view/helpers/capture_helper.rb
@@ -117,6 +117,28 @@ module ActionView
         @_content_for[name]
       end
 
+      # content_for? simply checks whether any content has been captured yet using content_for
+      # Useful to render parts of your layout differently based on what is in your views.
+      # 
+      # ==== Examples
+      #
+      # Perhaps you will use different css in you layout if no content_for :right_column
+      #
+      #   <%# This is the layout %>
+      #   <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
+      #   <head>
+      #	    <title>My Website</title>
+      #	    <%= yield :script %>
+      #   </head>
+      #   <body class="<%= content_for?(:right_col) ? 'one-column' : 'two-column' %>">
+      #     <%= yield %>
+      #     <%= yield :right_col %>
+      #   </body>
+      #   </html>
+      def content_for?(name)
+        @_content_for[name].present?
+      end
+
       # Use an alternate output buffer for the duration of the block.
       # Defaults to a new empty string.
       def with_output_buffer(buf = nil) #:nodoc:
diff --git a/actionpack/lib/action_view/helpers/form_tag_helper.rb b/actionpack/lib/action_view/helpers/form_tag_helper.rb
index 8ab78e7bc6..ca6ba501e2 100644
--- a/actionpack/lib/action_view/helpers/form_tag_helper.rb
+++ b/actionpack/lib/action_view/helpers/form_tag_helper.rb
@@ -231,6 +231,8 @@ module ActionView
       # * <tt>:rows</tt> - Specify the number of rows in the textarea
       # * <tt>:cols</tt> - Specify the number of columns in the textarea
       # * <tt>:disabled</tt> - If set to true, the user will not be able to use this input.
+      # * <tt>:escape</tt> - By default, the contents of the text input are HTML escaped.
+      #   If you need unescaped contents, set this to false.
       # * Any other key creates standard HTML attributes for the tag.
       #
       # ==== Examples
@@ -258,6 +260,9 @@ module ActionView
           options["cols"], options["rows"] = size.split("x") if size.respond_to?(:split)
         end
 
+        escape = options.key?("escape") ? options.delete("escape") : true
+        content = html_escape(content) if escape
+
         content_tag :textarea, content, { "name" => name, "id" => sanitize_to_id(name) }.update(options.stringify_keys)
       end