A little 'patch' to rubzip making possible to unzip files with StringIO

unzip_in_mem.rb

# To make possible unzip in-memory Zip files with StringIO
module Zip
  
  class ZipInputStream 
    def initialize(filename, offset = 0)
      super()
      @archiveIO = filename.class == String ? File.open(filename, "rb") : filename
      @archiveIO.seek(offset, IO::SEEK_SET)
      @decompressor = NullDecompressor.instance
      @currentEntry = nil
    end
  end
  
  class ::StringIO
    alias :old_read :read
    def read(length, buffer=nil)
      buffer ? old_read(length, buffer) : old_read(length)
    end
  end

end