Bug 249235 – CSSToStyleMap::mapNinePieceImage doesn't take into account that the CSSBorderImageWidthValue may be omitted.

• Component: CSS
• Status: NEW

[Oriol Brufau]

```
var s = document.body.style;
var cs = getComputedStyle(document.body);

s.webkitBoxReflect = "left 0px url() 3 / 4% / 5px";
cs.webkitBoxReflect; // "left 0px url(\"\") 3 fill / 4% / 5px stretch"

s.webkitBoxReflect = "left 0px url() 3 // 5px";
cs.webkitBoxReflect; // Actual: "left 0px url(\"\") 3 fill / auto / 0 stretch"
                     // Expected: "left 0px url(\"\") 3 fill / auto / 5px stretch"
```

-webkit-border-image and -webkit-mask-box-image had the same problem before they became shorthands in bug 237487 and bug 249115.

[Radar WebKit Bug Importer]

<rdar://problem/103561057>