User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:96.0) Gecko/20100101 Firefox/96.0

Steps to reproduce:

Open attached "a-outline-broken.html"

Actual results:

Outline rectangle is too small.

Expected results:

Outline rectangle should be tracing image borders. It should encompass whole area where "a" is active.

Rendering comparison between Firefox 95 and Firefox 96.

mozregression points to https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=47d2418f7eec36d8c55fb6b7c5833aaafb801d90&tochange=1b335acf7f139b32671a75980be0d78149e31973 which has only one change, related to Bug 1739894.

So Blink special-cases inline boxes to include descendants:

https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/core/layout/layout_inline.cc;l=1860;drc=7a187fc6fc0d1c505bb30f143c1f10f73e8904e4

That seems fairly unfortunate? But perhaps ok.

(In reply to Rinat from comment #0)

Outline rectangle should be tracing image borders. It should encompass whole area where "a" is active.

FWIW that's not what other browsers do either if I tweak your test-case a bit, as per the above.

I can't make much sense of what Blink is doing here tbh.

So I think for now a safe and easy patch would be to just special-case inline frames to always include overflow areas (effectively reverting to our previous behavior), wdyt Daniel?

Yeah, that sounds fine to me.

(We should double-check what other browsers do for block-in-inline splits and abspos children inside of inline frames, and make sure the change doesn't cause us to take a step away from compatibility for those cases.)

Actually, WebKit behaves like us, so I think I'd rather wait for https://github.com/w3c/csswg-drafts/issues/6981 to get resolved to potentially change this.

Set release status flags based on info from the regressing bug 1739894

Emilio, should we do something in FF until the spec is updated, or should we continue to wait for the spec update?

I don't think we should change behavior again until the spec is clarified.

We're seeing some site breakage, but they're only minor visual issues, so setting P3 for the moment.

I ran into this today at Fidelity (Mozilla's 401k retirement-account provider in the US).

STR there are to log in & view your 401k account, go to the "Investments" tab, then "Choose my investments", and then "Exchange multiple investments".

This puts you on a page with a "Start Your Rebalance" button which looks quite broken when clicked (which gives it focus before the page load happens). See attached screenshot.