Consider merging https://chromium.googlesource.com/chromium/blink/+/771dc814b28496295ded1ac67346d774f4ebd608 Fixed position element was rendered as normal flow irrespective of it's relative-position-parents. if fixed position element does not have left and/or right position then it should render as normal flow with respect to it's parent. So fixed position element is shifted with the value of relative position of it's parent.
<rdar://problem/99352377>
Created attachment 462017 [details] Test case
Created attachment 466955 [details] GitHub Patch Screenshot I manage to make this Blink patch work but I am sure, I did error because we start regressing some other tests as well. If someone can help or point me to right direction, it would be great. It although also progresses few failing test cases (Case 11 & Case 12) as well.
It has follow-up bug as well: https://src.chromium.org/viewvc/blink?view=revision&revision=185274 So I think we need to merge both. Hence, my patch might have not worked.