We've historically asserted that no "saturated" size values end up as
final metrics for boxes in layout. This always had a chance of producing
false positives, since you can trivially create extremely large boxes
with CSS.
The reason we had those assertions was to catch bugs in our own engine
code where we'd incorrectly end up with non-finite values in layout
algorithms. At this point, we've found and fixed all known bugs of that
nature, and what remains are a bunch of false positives on pages that
create very large scrollable areas, iframes etc.
So, let's change it! We now clamp content width and height of boxes to
17895700 pixels, apparently the same cap as Firefox uses.
There's also the issue of calc() being able to produce non-finite
values. Note that we don't clamp the result of calc() directly, but
instead just clamp values when assigning them to content sizes.
Fixes#645.
Fixes#1236.
Fixes#1249.
Fixes#1908.
Fixes#3057.
This fixes the very, _very_ slow loading of https://yzy-sply.com. The
`apply_style()` method also calls into this method recursively, so we
just need to call it once instead of once per node in the continuation
chain.
Before this change, it was possible for a second GC to get triggered
in the middle of a first GC, due to allocations happening in the
FinalizationRegistry cleanup host hook. To avoid this causing problems,
we add a "post-GC task" mechanism and use that to invoke the host hook
once all other GC activity is finished, and we've unset the "collecting
garbage" flag.
Note that the test included here only fails reliably when running with
the -g flag (collect garbage after each allocation).
Fixes#3051
