Reproduction link

https://ant.design/components/input#input-demo-allowclear

Steps to reproduce

1. Focus input with allowClear prop set to true
2. Write something
3. Press Tab

What is expected?

The clear button to be focused.

What is actually happening?

Next interactive element is focused.

After adding tabIndex={-1} in this PR react-component/input#111 the clear button became inaccessible breaking WCAG success criterions 2.1.1 and 2.1.3, keyboard users cannot focus and operate this functionality and it produces inequality.

Instead of adding tabIndex={-1} it is better to add button outline that is reset here https://github.com/ant-design/ant-design/blob/master/components/input/style/index.ts#L407. In this case users can visually identify the focus state and it will be clear why second Tab is needed to move to other elements.