lib/active_support/json/encoding.rb in activesupport-3.2.13 vs lib/active_support/json/encoding.rb in activesupport-3.2.14.rc1

@@ -120,10 +120,16 @@
 
         def escape(string)
           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] }
+          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 = %("#{json}")
           json.force_encoding(::Encoding::UTF_8) if json.respond_to?(:force_encoding)
           json
         end
       end