gistfile1.txt

#!/usr/bin/ruby

require 'pathname'


system "rm -rf /tmp/x /tmp/foo"
Dir.mkdir "/tmp/x" 
Dir.mkdir "/tmp/x/y" 
File.open "/tmp/x/y/z", "w"  do |f|
  f.puts "hello world"
end
Dir.chdir "/tmp"
File.symlink "/tmp/x/y", "foo"

orig_path = "/tmp/foo/../y/z"
File.stat "/tmp/foo/z" # works
File.stat orig_path # works
puts "all these work so far, now let's cleanpath it"

clean_path = Pathname.new(orig_path).cleanpath

File.stat clean_path # fails, because of a faulty path cleaning algorithm