This patch fixes an issue where grid items using `grid-area: <name>`
with no matching named grid area or lines would be incorrectly placed
at position 0.
According to https://www.w3.org/TR/css-grid-1/#line-placement:
1. When a `<custom-ident>` doesn't match any named line, placement
should fall back to the first implicit grid line
2. When the same `<custom-ident>` is given for both `grid-*-start` and
`grid-*-end` (which happens with `grid-area: name`), and both fall
back to the same implicit line, the resulting span is 1
Previously, the fallback values were hardcoded to 0 and 1, which placed
items in track 0. The fix changes the fallback to use
`m_explicit_line_count` (the first implicit line index) for both start
and end identifiers. When both reference the same line (start == end),
the existing "both positioned" logic now handles this by setting span=1
and adjusting end accordingly.
Per the CSS Namespaces spec, an empty string declared in an
@namespace rule represents no namespace.
Fixes WPT:
- css/css-namespaces/prefix-002.xml
- css/css-namespaces/prefix-003.xml
The CSS spec says the baseline of an inline-block should be the bottom
margin when either the overflow property is not 'visible' or there are
no in-flow line boxes. Previously, only the latter case was checked.
This fixes 1 WPT test:
https://wpt.live/css/css-align/baseline-of-scrollable-1a.html
This fixes an issue where text decorations (e.g. underlines) of text
split across multiple fragments would have unintended 1px gaps.
Gains us 2 WPT passes (imported)
Implements `::slotted()` to enough extent we could pass the imported WPT
test and make substantial layout correctness improvement on
https://www.rottentomatoes.com/
If `will-change` is set to a property value where that property could
create a stacking context, then we create a stacking context regardless
of the current value of that property.
This tests is trying to see if we're taking into account the full margin
box width (75px - 50px) when determining whether there is enough space
to fit the BFC box. No major browser passes this test, and other tests
such as `css/CSS2/floats/new-fc-beside-float-with-margin.html` seem to
require that we ignore those margins.
We don't yet have a system for "legacy value aliases", but until we have
a lot of them we can handle them manually.
We also have to do this in two places because
parse_css_value_for_property() doesn't call any property-specific
parsing code.
With this, we pass the 8 ref tests in css/selectors/selectors-4/ which
previously failed. This is not technically a full implementation, as we
are supposed to first canonicalize the language range and tag, but that
will require downloading and processing the IANA language subtag
registry:
https://www.iana.org/assignments/language-subtag-registry/language-subtag-registry
That's significantly more work, and WPT doesn't seem to test any cases
that require that, so we can leave it for now.
The contain-paint-stacking-context-001a.html test has been removed
for now because it has a 1px tall blue line at the top that should
not be there. With paint containment, this line is removed only in
the actual test case, but not in the reference. This is because of
the font that we use in testing and happens in Chromium as well if
the test is run with that font.
