/**
  * Удаляет сегменты с точками из пути.
  *
  * Алгоритм описан по ссылке:
  * https://tools.ietf.org/html/rfc3986#section-5.2.4
  *
  */
function removeDotSegments(path) {
  var output = [];
  var offset = 0;
  var position;
  var segment;
  // While the input buffer is not empty, loop as follows:
  for (;;) {
    console.log(path.substr(offset));
    // A.  If the input buffer begins with a prefix of "../" or "./",
    //     then remove that prefix from the input buffer; otherwise,
    if (path.substr(offset, 3) === '../') {
      offset += 2;
      continue;
    }
    if (path.substr(offset, 2) === './') {
      ++offset;
      continue;
    }
    // B.  if the input buffer begins with a prefix of "/./" or "/.",
    //     where "." is a complete path segment, then replace that
    //     prefix with "/" in the input buffer; otherwise,
    if (path.substr(offset, 3) === '/./') {
      offset += 2;
      continue;
    }
    // C.  if the input buffer begins with a prefix of "/../" or "/..",
    //     where ".." is a complete path segment, then replace that
    //     prefix with "/" in the input buffer and remove the last
    //     segment and its preceding "/" (if any) from the output
    //     buffer; otherwise,
    if (path.substr(offset, 4) === '/../') {
      offset += 3;
      output.pop();
      continue;
    }
    // D.  if the input buffer consists only of "." or "..", then remove
    //     that from the input buffer; otherwise,
    //
    // E.  move the first path segment in the input buffer to the end of
    //     the output buffer, including the initial "/" character (if
    //     any) and any subsequent characters up to, but not including,
    //     the next "/" character or the end of the input buffer.
    position = path.indexOf('/', offset + 1);
    if (position === -1) {
      segment = path.substr(offset);
      if (segment === '/.') {
        // Второе условие A
        output.push('/');
      } else if (segment === '/..') {
        // Второе условие B
        output.pop();
        output.push('/');
      } else if (segment !== '.' && segment !== '..') {
        // D
        output.push(segment);
      }
      break;
    }
    // E
    segment = path.substr(offset, position);
    output.push(segment);
    offset = position;
  }
  return output.join('');
}


var paths = [
  '/a/b/c/./../../g',
  'mid/content=5/../6',
];
paths.forEach((path) => {
  console.log('%s --> %s', path, removeDotSegments(path));
});