padrino-cache ArgumentError: invalid byte sequence in UTF-8

padrino-cache-invalid-byte-seq-utf8.rb

require 'redis'
require "active_support/core_ext/string/multibyte"
require "active_support/core_ext/object/blank"

redis = Redis.new

good_string = "...............................................................................\n\n...............................................................................\n\n...............................................................................\n\n...............................................................................\n\n\n.........................................................."

bad_string  = "...............................................................................\n\n...............................................................................\n\n...............................................................................\n\n...............................................................................\n\n\n..........................................................\n"
 
foo_dump = Marshal.dump({:response_buffer => good_string, :content_type => :html})
bar_dump = Marshal.dump({:response_buffer => bad_string, :content_type => :html})

foo_dump.is_utf8? # => true
bar_dump.is_utf8? # => false

foo_dump.blank? # => false
bar_dump.blank? # => false

redis.set "foo", foo_dump
redis.set "bar", bar_dump

foo_value = redis.get "foo"
# => "\u0004\b{\a:\u0014response_bufferI\"\u0002\u007F\u0001...[etc.]...\u0006:\u0006ET:\u0011content_type:\thtml"
bar_value = redis.get "bar"
# => "\u0004\b{\a:\u0014response_bufferI\"\u0002\x80\u0001...[etc.]...\n\u0006:\u0006ET:\u0011content_type:\thtml"

foo_value.is_utf8? # => true
bar_value.is_utf8? # => false

foo_value.blank? # => false
bar_value.blank? # => ArgumentError: invalid byte sequence in UTF-8