Function updatePortal

code/composition/public/app.js:9181–9193

(returnFiber, current, portal, expirationTime)

  }

  function updatePortal(returnFiber, current, portal, expirationTime) {
    if (current === null || current.tag !== HostPortal || current.stateNode.containerInfo !== portal.containerInfo || current.stateNode.implementation !== portal.implementation) {
      // Insert
      var created = createFiberFromPortal(portal, returnFiber.mode, expirationTime);
      created['return'] = returnFiber;
      return created;
    } else {
      // Update
      var existing = useFiber(current, portal.children || [], expirationTime);
      existing['return'] = returnFiber;
      return existing;
    }
  }

  function updateFragment(returnFiber, current, fragment, expirationTime, key) {
    if (current === null || current.tag !== Fragment) {