Quick fix for not escaping []s (not ideal)

activesupport/lib/active_support/core_ext/object/to_query.rb

@@ -7,7 +7,7 @@ class Object
   # Note: This method is defined as a default implementation for all Objects for Hash#to_query to work.
   def to_query(key)
     require 'cgi' unless defined?(CGI) && defined?(CGI::escape)
-    "#{CGI.escape(key.to_s)}=#{CGI.escape(to_param.to_s)}"
+    "#{CGI.escape(key.to_s).gsub(/%(5B|5D)/n) { [$1].pack('H*') }}=#{CGI.escape(to_param.to_s)}"
   end
 end