overflow meet flex

Description

如果将某个盒子设为伸缩盒(display: flex;)，要注意子元素及其后代元素是否有white-space样式修饰，它会影响flex，使其失效，甚至使子元素溢出父元素。

Test Code

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>test</title>
  <style>
    #father {
      width: 200px;
      height: 200px;
      background: #bfa;
      display: flex;
    }
    #son {
      flex: 3;
      height: 90%;
      background: orange;
    }
    #daughter {
      flex: 7;
      height: 90%;
      background: pink;
    }
    pre {
      background: green;
      /*overflow: auto;*/
    }
    .test {
      /*white-space: pre;*/
      /*white-space: nowrap;*/
      white-space: normal;
      /*white-space: pre-wrap;*/
    }
  </style>
</head>
<body>

  <div id="father">
    <div id="daughter"></div>
    <div id="son">
<!--      <pre>-->
<!--        overflow-->
<!--      </pre>-->
      <div class="test">
        responsibility
        overflow overflow overflow
      </div>
    </div>
  </div>

</body>
</html>

Result

正常时

flex失效

甚至子元素溢出父元素