1979805 - `contain:intrinsic-size; content-visibility:auto` causes `contain-intrinsic-height` to behave as if it were `0`

Status: NEW

(Core :: Layout, defect)

Description

[Daniel Holbert [:dholbert]]

STR:

1. Load attached testcase.

ACTUAL RESULTS:
Alert shows FAIL; got scrollHeight of 5000 but expected 21000

EXPECTED RESULTS:
Alert should show PASS; got scrollHeight of 21000 which is what we expect

NOTES:
scrollHeight is an estimate of the actual content-height, due to content-visibility: auto;, but it's a giant under-estimate here -- our reported 5000px is just the height of the spacer element, and it doesn't include the heights of any of the product-item divs.

If I remove contain: inline-size from the testcase, then we give expected-results. So I think the issue is that contain: inline-size is making us behave as if our used contain-intrinsic-height were 0px.

If I remove contain:inline-size, or if I change it to contain:size, then we get expected-results here.

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: testcase 1

Comment 2

[Daniel Holbert [:dholbert]]

I believe this is the root cause of webcompat site-report bug 1978276.