1 files changed, 6 insertions, 6 deletions
diff --git a/lib/cgi/util.rb b/lib/cgi/util.rb
index b7b0233b4d..218bdbdd9a 100644
--- a/lib/cgi/util.rb
+++ b/lib/cgi/util.rb
@@ -9,14 +9,14 @@ class CGI
   end
 
 
-  # URL-decode a string.
+  # URL-decode a string with encoding(optional).
   #   string = CGI::unescape("%27Stop%21%27+said+Fred")
   #      # => "'Stop!' said Fred"
-  def CGI::unescape(string)
-    enc = string.encoding
-    string.tr('+', ' ').gsub(/((?:%[0-9a-fA-F]{2})+)/) do
-      [$1.delete('%')].pack('H*').force_encoding(enc)
-    end
+  def CGI::unescape(string,encoding=@@accept_charset)
+    str=string.tr('+', ' ').gsub(/((?:%[0-9a-fA-F]{2})+)/) do
+      [$1.delete('%')].pack('H*')
+    end.force_encoding(encoding)
+    str.valid_encoding? ? str : str.force_encoding(string.encoding)
   end
 
   TABLE_FOR_ESCAPE_HTML__ = {