Created attachment 437499 [details] Test case In the attached test case, the position: absolute child is not clipped by its containing block (a transformed div with overflow: auto) and instead spills out of the bounds of this element.
Created attachment 437500 [details] Image showing failure
<rdar://problem/83101942>
I'm still able to reproduce this, but I'm currently only seeing it on WebKitGTK and not the Mac port.
WinCairo is also having this issue even with disabling Accelerated Compositing. Cairo clipping bug?
Mac MiniBrowser WK1 Window is also having this issue.
Created attachment 442461 [details] PDF exported by Safari TP 133 It can be observed by using "Export as PDF" of Safari.
*** This bug has been marked as a duplicate of bug 241641 ***