1483225 - Behaviour of SVG element with invalid mask differs from other browsers and W3C spec

Status: NEW

(Core :: SVG, defect, P3)

Description

[aziesemer]

Attachment: Test for Firefox SVG issue with masked elements

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/11.1.2 Safari/605.1.15

Steps to reproduce:

Open the following page (or the attached file) in different web browsers:
https://codepen.io/anon/pen/WKPwJr?editors=1000


Actual results:

This SVG has an undefined reference to a mask.
In Firefox, most of the SVG elements are hidden, but some are still visible.
Safari and Chrome ignore the mask, displaying everything.


Expected results:

There is a discussion at W3C about this issue:
https://github.com/w3c/fxtf-drafts/issues/130

It seems that the expected behaviour as of today is to hide everything, however they are discussing if they should change it ignore the mask and show everything (as Chrome and Safari do).

Despite that, Firefox is not following the spec either since not everything is hidden (possibly due to a bug).

Comment 1

[aziesemer]

Attachment: Screenshot Safari vs Firefox

Comment 2

[Cristian Craciun]

Managed to reproduce and set the proper component.

Comment 3

[Mats Palmgren (inactive)]

We should fix this per https://github.com/w3c/fxtf-drafts/issues/130:

RESOLVED: For clipping and masking, we follow the behavior of Edge, WebKit, and Blink in the https://github.com/w3c/fxtf-drafts/issues/130#issuecomment-390981529 table
RESOLVED: If a referenced filter is missing or invalid, the side effects like stacking context are still preserved.

This also affects CSS mask-image (so perhaps Web Painting is a more appropriate component?).