Merge pull request #8235 from tilsammans/dont_escape_actionmailer_when_plaintext

Introduce `ActionView::Template::Handlers::ERB.escape_whitelist`

Conflicts:
	actionpack/CHANGELOG.md
	actionpack/test/template/template_test.rb

actionpack/CHANGELOG.md

@@ -1,5 +1,12 @@
 ## Rails 3.2.10 (unreleased) ##
 
+*   Introduce `ActionView::Template::Handlers::ERB.escape_whitelist`. This is a list
+    of mime types where template text is not html escaped by default. It prevents `Jack & Joe`
+    from rendering as `Jack & Joe` for the whitelisted mime types. The default whitelist
+    contains text/plain. Fix #7976 [Backport #8235]
+
+    *Joost Baaij*
+
 *   `BestStandardsSupport` middleware now appends it's `X-UA-Compatible` value to app's
     returned value if any. Fix #8086 [Backport #8093]
 

actionpack/lib/action_view/template/handlers/erb.rb

@@ -48,6 +48,10 @@ module ActionView
         class_attribute :erb_implementation
         self.erb_implementation = Erubis
 
+        # Do not escape templates of these mime types.
+        class_attribute :escape_whitelist
+        self.escape_whitelist = ["text/plain"]
+
         ENCODING_TAG = Regexp.new("\\A(<%#{ENCODING_FLAG}-?%>)[ \\t]*")
 
         def self.call(template)
@@ -83,6 +87,7 @@ module ActionView
 
           self.class.erb_implementation.new(
             erb,
+            :escape => (self.class.escape_whitelist.include? template.mime_type),
             :trim => (self.class.erb_trim_mode == "-")
           ).src
         end

actionpack/test/template/template_test.rb

@@ -25,6 +25,10 @@ class TestERBTemplate < ActiveSupport::TestCase
       "Hello"
     end
 
+    def apostrophe
+      "l'apostrophe"
+    end
+
     def partial
       ActionView::Template.new(
         "<%= @virtual_path %>",
@@ -47,7 +51,7 @@ class TestERBTemplate < ActiveSupport::TestCase
     end
   end
 
-  def new_template(body = "<%= hello %>", details = {})
+  def new_template(body = "<%= hello %>", details = { :format => :html })
     ActionView::Template.new(body, "hello template", ERBHandler, {:virtual_path => "hello"}.merge!(details))
   end
 
@@ -64,6 +68,16 @@ class TestERBTemplate < ActiveSupport::TestCase
     assert_equal "Hello", render
   end
 
+  def test_basic_template_does_html_escape
+    @template = new_template("<%= apostrophe %>")
+    assert_equal "l&#x27;apostrophe", render
+  end
+
+  def test_text_template_does_not_html_escape
+    @template = new_template("<%= apostrophe %>", :format => :text)
+    assert_equal "l'apostrophe", render
+  end
+
   def test_template_loses_its_source_after_rendering
     @template = new_template
     render