def cleanup(path)
if path.respond_to?(:encoding)
encoding = path.encoding
dot = '.'.encode(encoding)
slash = '/'.encode(encoding)
backslash = '\\'.encode(encoding)
else
dot = '.'
slash = '/'
backslash = '\\'
end
parts = []
unescaped = path.gsub(/%2e/i, dot).gsub(/%2f/i, slash).gsub(/%5c/i, backslash)
unescaped = unescaped.gsub(backslash, slash)
unescaped.split(slash).each do |part|
next if part.empty? or part == dot
part == '..' ? parts.pop : parts << part
end
cleaned = slash + parts.join(slash)
cleaned << slash if parts.any? and unescaped =~ %r{/\.{0,2}$}
cleaned
end