Bug 260342 – clip-path on SVG content should default to using the border-box (aka stroke-box)

• Component: SVG
• Status: RESOLVED CONFIGURATION CHANGED

[Philip Rogers]

Created attachment 467305 [details]
Testcase showing two clip-paths that should render the same

In the attached testcase we have 2 stroked green boxes with clip-paths of "inset(0)" and "inset(0) border-box". These should render the same due to the following lines in http://www.w3.org/TR/css-masking-1/#the-clip-path:
1. If no reference box is specified, the border-box will be used as
  reference box.
2. For SVG elements without an associated CSS layout box, the used
  value for ... border-box and margin-box is stroke-box.

I found this while working on bringing Chromium's clip-path implementation up to speed and found no engines agree on this. I plan to land two new WPT tests covering this behavior (css/css-masking/clip-path-svg-content/clip-path-inset-stroke-001.svg and css/css-masking/clip-path-svg-content/clip-path-inset-stroke-002.svg).

[Radar WebKit Bug Importer]

<rdar://problem/114375393>

[Ahmad Saleem]

Both of these WPT test cases are passing - https://wpt.fyi/results/css/css-masking/clip-path-svg-content?label=master&label=experimental&aligned&q=clip-path-inset-stroke-00

as nearest as November 2023