Bug 151995 – Overflowing SVG is sometimes clipped at tile boundaries

• Status: NEW
• Component: SVG

[Simon Fraser (smfr)]

Created attachment 266901 [details]
Testcase

Attached testcase shows a bug where overflowing SVG is clipped sometimes.

The bug is that we treat the RenderSVGRoot as a layout boundary, but when it has overflow, we need to propagate layout to the containers, so that the inline boxes compute the correct overflow.

[Radar WebKit Bug Importer]

<rdar://problem/47122527>

[Ahmad Saleem]

I am able to reproduce this bug in Safari 15.6.1 and Safari Technology Preview 152 using attached test css and when the green tile goes to bottom right corner, it clips and does not show full box immediately and sometime it shows and sometime clipped. All other browsers (Chrome Canary 107 and Firefox Nightly 106) work fine. Thanks!

[Ahmad Saleem]

When I merge Blink's patch as part of bug 199364, this also get fixed. Tested locally.

Last time, I did the PR here - https://github.com/WebKit/WebKit/pull/9138

We can't merge Blink's patch (test cases) since they can be flaky.

[Ahmad Saleem]

@Karl - is it reproducible for you. It isn't reproducible to me anymore.

[Karl Dubost]

Ahmad, Simon,

I have two different behaviors:

Scenario A
1. Load the test case
2. stay on the window
Result: The green box after moving is not clipped

Scenario B
1. Load the test case
2. Go to the Finder
Result: The green box after moving is clipped

[Karl Dubost]

but if in Scenario B if I click on the window the box gets unclipped again.

[Karl Dubost]

Firefox and Chrome never clips the green box.

[Simon Fraser (smfr)]

You need to put the Safari window into the background to see the bug. It still reproduces.

[Simon Fraser (smfr)]

Turn on layer borders in web inspector to see the tiling change in background windows.