If the parent BFC can come up with a nice stretch-fit width for the flex
container, it will have already done so *before* even entering flex
layout. There's no need to do it again, midway through the flex layout
algorithm.
This wasn't just unnecessary, but we were also doing it incorrectly and
not taking margins into account when calculating the amount of available
space for stretch-fit. This led to oversized flex containers in the
presence of negative margins.
Fixes#18614
`Length::resolved(Node&)` transforms infinite values to "auto".
Following transformations:
Infinite (Length) -> "auto" -> 0 (px)
cause border-box width to be resolved in zero when it should be inf px.
Removing `Length::resolved(Node&)` makes it work right:
Infinite (Length) -> Infinite (px)
Fixes#18649
https://www.w3.org/TR/CSS22/visuren.html#floats says that when a box
establishes BFC it should not overlap with floats. The way to avoid
overlaps is up to implementor. This change implements avoiding overlap
by narrowing width of a box because it seems like what other engines
do (in the scenarios I tested).
When there are floats present inside an IFC, we must coordinate with
the parent BFC to calculate the automatic width of the IFC's block box.
This is because the IFC is not directly aware of floats. Only the BFC
knows enough about them to account for them in automatic sizing.
This patch does three things:
- Factors out the code that determines whether a box will create a new
formatting context for its children (and which type of context)
- Uses that code to mark all formatting context roots in layout tree
dumps. This makes it much easier to follow along with layout since
you can now see exactly where control is transferred to a new
formatting context.
- Rebaselines all existing layout tests, since the output format has
changed slightly.
Fixes the problem that width is incorrectly computed in intrinsic
sizing mode when there are blocks that have min-width or max-width
specified.
Actually that is just the fix of a symptom of the larger problem that
Length::to_px() returns 0 when value is auto regardless of available
size.
If there is a remaining margin-bottom in margin collapsing state
tracker after laying out all boxes in the current BFC, it must be
assigned to the last in-flow child since margin collapsing cannot
occur across a formatting context boundary.
The current issue where margin-bottom may be counted twice due to
"collapse through" margins in the last in-flow child box is addressed
with this fix by excluding such boxes during the search for a box to
assign the remaining margin.
Test case coming with this fix has a layout bug with incorrectly
computed line height.
When calculating the intrinsic width of a block-level box, we now ignore
the preferred width entirely, and not just when the preferred width
should be treated as auto.
The condition for this was both confused and wrong, as it looked at the
available width around the box, but didn't check for a width constraint
on the box itself.
Just because the available width has an intrinsic sizing constraint
doesn't mean that the box is undergoing intrinsic sizing. It could also
be the box's containing block!
