Extracted from https://github.com/facebook/react/issues/12643.

We're currently diff a host node in the complete phase even if it has bailed out in the begin phase. By itself, this just means we're doing a little bit more work than necessary. But it also has some observable effects. In particular, https://github.com/facebook/react/issues/13424 (which by itself would be very rare and probably not worth fixing) is made worse because we end up committing update to inputs from another component.

I have a fix for this in https://github.com/facebook/react/pull/13423. Filing this for posterity.
} else {
      const container = portalOrRoot.containerInfo;
      let newChildSet = createContainerChildSet(container);
      
      appendAllChildrenToContainer(newChildSet, workInProgress);
      portalOrRoot.pendingChildren = newChildSet;
      
      markUpdate(workInProgress);
      finalizeContainerChildren(container, newChildSet);
    }
  };
  updateHostComponent = function(
    current: Fiber,
    workInProgress: Fiber,
    updatePayload: null | UpdatePayload,
    type: Type,
    oldProps: Props,
    newProps: Props,
    rootContainerInstance: Container,
    currentHostContext: HostContext,
  ) {
    
    
    const childrenUnchanged = workInProgress.firstEffect === null;
    const currentInstance = current.stateNode;
    if (childrenUnchanged && updatePayload === null) {
      
      
      workInProgress.stateNode = currentInstance;