Not 100% which bits here we match. At the very least, the following paragraph was added:
"When calculating the baseline according to the above rules, if the box contributing a baseline has an ‘overflow’ value that allows scrolling, the box must be treated as being in its initial scroll position for the purpose of determining its baseline."
*** Bug 84507 has been marked as a duplicate of this bug. ***
I think this was fixed in bug 96188. We can file new bugs if any additional issues come up.