Fix Breadcrumb falsy children, close #5015

components/breadcrumb/Breadcrumb.tsx

@@ -88,8 +88,11 @@ export default class Breadcrumb extends React.Component<BreadcrumbProps, any> {
       });
     } else if (children) {
       crumbs = React.Children.map(children, (element: any, index) => {
+        if (!element) {
+          return element;
+        }
         warning(
-          element && element.type.__ANT_BREADCRUMB_ITEM,
+          element.type && element.type.__ANT_BREADCRUMB_ITEM,
           'Breadcrumb only accetps Breadcrumb.Item as it\'s children'
         );
         return cloneElement(element, {

components/breadcrumb/__tests__/Breadcrumb.test.js

@@ -1,6 +1,7 @@
 import React from 'react';
-import { mount } from 'enzyme';
-import Breadcrumb from '../Breadcrumb';
+import { mount, render } from 'enzyme';
+import { renderToJson } from 'enzyme-to-json';
+import Breadcrumb from '../index';
 
 describe('Breadcrumb', () => {
   it('warns on non-Breadcrumb.Item children', () => {
@@ -18,4 +19,18 @@ describe('Breadcrumb', () => {
       'Breadcrumb only accetps Breadcrumb.Item as it\'s children'
     );
   });
+
+  // https://github.com/ant-design/ant-design/issues/5015
+  it('should allow Breadcrumb.Item is null or undefined', () => {
+    const wrapper = render(
+      <Breadcrumb>
+        {null}
+        <Breadcrumb.Item>Home</Breadcrumb.Item>
+        {undefined}
+      </Breadcrumb>
+    );
+    // eslint-disable-next-line
+    expect(console.error.calls).toBe(undefined);
+    expect(renderToJson(wrapper)).toMatchSnapshot();
+  });
 });

components/breadcrumb/demo/basic.md

@@ -1,6 +1,6 @@
 ---
 order: 0
-title:   
+title:
   zh-CN: 基本
   en-US: Basic Usage
 ---