The static-position rectangle for absolutely positioned flex children
still mapped cross-axis flex-start and flex-end directly to physical
start and end. That broke cases where the flex cross axis is reversed
by writing mode, direction, or wrap-reverse.
Teach the flex formatting context to derive the cross-axis direction
from its logical axes and wrap mode, and use that when resolving
cross-axis alignment for abspos static positioning. This clears the
newly imported position-absolute-013 test and improves a broader set
of existing flex abspos WPT baselines.
Handle flex main and cross axes in logical terms so percentage
height resolution keeps working in vertical writing modes and
other orthogonal cases. Also let resolvable percentage max
cross sizes clamp stretched flex items.
The same change improves a broader set of imported css-flexbox
tests than the original percentage-heights cases. Update the
affected expectations in the same change so the resulting
behavior stays documented and the suite remains green.
Originally, 7200b3a16c introduced a two-pass system to determine
hypothetical cross sizes. Later, this was partially reverted in
0084d992d4, but some code was left behind that caused resolution of
percentages in `{min/max}-{width/height}` size constraints not to work.
Through intrinsic sizing, we can potentially end up with a definite
available space for the items in the last FC run. At that point we
should be able to resolve percentages against the available space, but
we were never doing that.
...instead of taking the Layout::Box. This will allow us to make more
nuanced decisions in those functions by having access to flex layout
internal state.
There's a specific (and thankfully very common!) scenario where we can
actually skip calculating the automatic minimum size for flex items.
In single-line (no wrapping) flex containers, if the sum of all item
flex base sizes is <= the flex container's main size, we know that
none of the items will be shrunk by the layout algorithm.
And so for any flex item with definite main size AND automatic minimum
main size, we can treat the automatic minimum size as 0.
Resulting in a massive rename across almost everywhere! Alongside the
namespace change, we now have the following names:
* JS::NonnullGCPtr -> GC::Ref
* JS::GCPtr -> GC::Ptr
* JS::HeapFunction -> GC::Function
* JS::CellImpl -> GC::Cell
* JS::Handle -> GC::Root
If available space is definite it should always match the size of the
containing block. Therefore, there is no need to do containing block
node lookup.
