simple_format returns a safe buffer escaping unsafe input [Santiago P…

…astorino] (Closes #3767)

Signed-off-by: David Heinemeier Hansson <david@loudthinking.com>

actionpack/lib/action_view/helpers/text_helper.rb

@@ -323,12 +323,12 @@ def markdown(text)
       #   # => "<p class='description'>Look ma! A class!</p>"
       def simple_format(text, html_options={})
         start_tag = tag('p', html_options, true)
-        text = text.to_s.dup
+        text = h(text)
         text.gsub!(/\r\n?/, "\n")                    # \r\n and \r -> \n
         text.gsub!(/\n\n+/, "</p>\n\n#{start_tag}")  # 2+ newline  -> paragraph
         text.gsub!(/([^\n]\n)(?=[^\n])/, '\1<br />') # 1 newline   -> br
         text.insert 0, start_tag
-        text << "</p>"
+        text.safe_concat "</p>"
       end
 
       # Turns all URLs and e-mail addresses into clickable links. The <tt>:link</tt> option

actionpack/test/template/text_helper_test.rb

@@ -39,6 +39,18 @@ def test_simple_format
      assert_equal %Q(<p class="test">para 1</p>\n\n<p class="test">para 2</p>), simple_format("para 1\n\npara 2", :class => 'test')
   end
 
+  def test_simple_format_should_be_html_safe
+    assert simple_format("<b> test with html tags </b>").html_safe?
+  end
+
+  def test_simple_format_should_escape_unsafe_input
+    assert_equal "<p>&lt;b&gt; test with unsafe string &lt;/b&gt;</p>", simple_format("<b> test with unsafe string </b>")
+  end
+
+  def test_simple_format_should_not_escape_safe_input
+    assert_equal "<p><b> test with safe string </b></p>", simple_format("<b> test with safe string </b>".html_safe)
+  end
+
   def test_truncate
     assert_equal "Hello World!", truncate("Hello World!", :length => 12)
     assert_equal "Hello Wor...", truncate("Hello World!!", :length => 12)