[filter-effects] What's the order of applying filters and `overflow`?

[smfr]

https://drafts.fxtf.org/filter-effects/#FilterProperty says:

The compositing model follows the SVG compositing model [SVG11]: first any filter effect is applied, then any clipping, masking and opacity. As per SVG, the application of filter has no effect on hit-testing.

which implies that overflow (a type of clipping) is applied after the filter. This suggests that overflow:clip would clip out the part of a drop-shadow filter that extends outside the box. However, Chrome and Firefox don't do this, but WebKit does.

Test: https://codepen.io/smfr/pen/XJbRaeb

Or does the clipping above only apply to clip-path, which is more akin to SVG-style clipping?

[smfr]

css/filter-effects/blur-clip-stacking-context-002.html tests that the blur is not clipped. @emilio how did you deduce that from the specs?

[faceless2]

Surely filter would be in the same category as box-shadow - it's ink-overflow not scrolling-overflow, so is not clipped by overflow. It would be an odd result if box-shadow was not clipped but filter:drop-shadow was.

https://drafts.csswg.org/css-overflow-3/#ink-overflow