Bug 225120 - SVG filter is applied twice when applied to the root <svg> element
Summary: SVG filter is applied twice when applied to the root <svg> element
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: SVG (show other bugs)
Version: Safari 14
Hardware: Mac (Intel) macOS 11
: P2 Normal
Assignee: Kiet Ho
URL: https://codepen.io/xiaolong-li/pen/Yz...
Keywords: InRadar
: 139281 (view as bug list)
Depends on:
Blocks: 260152 262180
  Show dependency tree / graph
 
Reported: 2021-04-27 13:19 PDT by Xiaolong Li
Modified: 2023-11-29 12:22 PST (History)
6 users (show)

See Also:

Attachments
reduced test case (537 bytes, text/html)
2023-06-06 13:22 PDT, Said Abou-Hallawa 		no flags Details
View All Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description Xiaolong Li 2021-04-27 13:19:51 PDT 
The issue happens when defining a filter inside an <svg> element and directly reference/apply it on the <svg> element itself. In this case, Safari seems to "over-apply" the effect, and one guess is that it may have applied the effect twice.

This issue doesn't appear in Chrome or Firefox. I also checked SVG spec and this is a legal structure.

If I move the filter attribute to a sub-element of the <svg>, then it works correctly.

Here is an example in CodePen demonstrating this. Opening it in Safari/Firefox/Chrome to see the difference: https://codepen.io/xiaolong-li/pen/YzNMZpM

I found an existing bug (https://bugs.webkit.org/show_bug.cgi?id=139281) that may be related to this, but not sure.
Comment 1 Radar WebKit Bug Importer 2021-05-04 13:20:15 PDT 
<rdar://problem/77522728>
Comment 2 Said Abou-Hallawa 2023-06-06 13:21:08 PDT 
This is correct. When the SVGFilter is applied to the <svg> root element, it is applied as an SVGFilter and it is also applied as CSSFilter referencing this SVGFilter.
Comment 3 Said Abou-Hallawa 2023-06-06 13:22:04 PDT 
Created attachment 466605 [details]
reduced test case
Comment 4 Kiet Ho 2023-06-08 11:22:18 PDT 
Pull request: https://github.com/WebKit/WebKit/pull/14780
Comment 5 EWS 2023-06-13 14:26:57 PDT 
Committed 265135@main (0dac14ca10cb): <https://commits.webkit.org/265135@main>

Reviewed commits have been landed. Closing PR #14780 and removing active labels.
Comment 6 Kiet Ho 2023-06-13 23:42:09 PDT 
*** Bug 139281 has been marked as a duplicate of this bug. ***