1 files changed, 2 insertions, 8 deletions
diff --git a/activesupport/lib/active_support/json/encoding.rb b/activesupport/lib/active_support/json/encoding.rb
index 91e4f07c6c..a50e6524c6 100644
--- a/activesupport/lib/active_support/json/encoding.rb
+++ b/activesupport/lib/active_support/json/encoding.rb
@@ -61,7 +61,7 @@ module ActiveSupport
             # hashes and arrays need to get encoder in the options, so that they can detect circular references
             options.merge(:encoder => self)
           else
-            options
+            options.dup
           end
         end
 
@@ -122,13 +122,7 @@ module ActiveSupport
           if string.respond_to?(:force_encoding)
             string = string.encode(::Encoding::UTF_8, :undef => :replace).force_encoding(::Encoding::BINARY)
           end
-          json = string.
-            gsub(escape_regex) { |s| ESCAPED_CHARS[s] }.
-            gsub(/([\xC0-\xDF][\x80-\xBF]|
-                   [\xE0-\xEF][\x80-\xBF]{2}|
-                   [\xF0-\xF7][\x80-\xBF]{3})+/nx) { |s|
-            s.unpack("U*").pack("n*").unpack("H*")[0].gsub(/.{4}/n, '\\\\u\&')
-          }
+          json = string.gsub(escape_regex) { |s| ESCAPED_CHARS[s] }
           json = %("#{json}")
           json.force_encoding(::Encoding::UTF_8) if json.respond_to?(:force_encoding)
           json