Bug 248113

Summary:	Serialization of computed -webkit-border-image doesn't round-trip for border-image-slice
Product:	WebKit	Reporter:	Oriol Brufau <obrufau>
Component:	CSS	Assignee:	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 2022-11-18 17:37:43 PST

-webkit-border-image automatically adds 'fill' to border-image-slice, except if the value is omitted.

Then, run this:

var s = document.body.style;
var cs = getComputedStyle(document.body);
s.borderImage = "url()";
cs.webkitBorderImage; // "url(\"\") 100% / 1 / 0 stretch"
s.webkitBorderImage = cs.webkitBorderImage;
cs.webkitBorderImage; // "url(\"\") 100% fill / 1 / 0 stretch"

No round-tripping!

So when serializing the computed -webkit-border-image,
 - If border-image-slice has fill, serialize normally (no change).
 - Else, if border-image-slice is 100%, serialize omitting the slice.
 - Else, serialize as empty string.

Comment 1 Radar WebKit Bug Importer 2022-11-25 17:38:15 PST

<rdar://problem/102674869>