Percentage size flex items in border-box container are sized incorrectly #423
Description
This is a followup from #422.
The size of percentage sized flex items in a border-box container is calculated relative to the container's border box size, but it should be relative to the container's inner size.
Example
<!DOCTYPE html>
<html>
<head>
<style>
.flexbox {
display: flex;
flex-direction: column;
justify-content: space-around;
height: 500px;
width: 300px;
padding: 100px;
box-sizing: border-box;
background-color: blue;
}
.test {
flex-grow: 0;
flex-basis: 50%;
box-sizing: content-box;
background-color: red;
}
</style>
</head>
<body>
<div class="flexbox">
<div class="test">test</div>
</div>
</body>
</html>Expected:
Actual:
