Bug 249235

Summary: CSSToStyleMap::mapNinePieceImage doesn't take into account that the CSSBorderImageWidthValue may be omitted.
Product: WebKit Reporter: Oriol Brufau <obrufau>
Component: CSSAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   

Description Oriol Brufau 2022-12-13 09:55:22 PST 
```
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.
Comment 1 Radar WebKit Bug Importer 2022-12-20 09:56:16 PST 
<rdar://problem/103561057>