Previously, `CSSStyleSheet.replace()` and `CSSStyleSheet.replaceSync()`
parsed the given CSS text into a temporary stylesheet object, from
which a list of rules was extracted. Doing this had the unintended
side-effect that a fetch request would be started if the given CSS text
referenced any external resources. This fetch request would cause a
crash, since the temporary stylesheet object didn't set the constructed
flag, or constructor document. We now parse the given CSS text as a
list of rules without constructing a temporary stylesheet.
Before this change, we'd skip storing the new ComputedProperties in
Element::recompute_style() if there was no invalidation needed.
This caused us to lose the information about which properties are
inherited and/or important (which is also carried by ComputedProperties,
but doesn't affect invalidation).
Consequently, we'd then fail to recompute inherited styles, since that
mechanism depends on this data.
The fix is simply to always store the new ComputedProperties.
This fixes one source of flakiness on WPT (of many) where we wouldn't
recompute style after programmatically altering the contents of a style
sheet, but instead had to wait for something else to cause invalidation.
This commit disallows "default" as a font-family name, when the name is
not quoted because unquoted names are treated as custom-idents, for
which the name "default" is not allowed.
Shorthand subproperties that match their initial values are now
excluded from serialization, by default.
Properties where this behavior is not desired, like `gap`, are
special-cased.
Previously, when serializing a time value, we would always convert it
to seconds. We now canonicalize the time value only when serializing
its computed value.
This implementation also fixes an issue where the individual components
of the `border-radius` shorthand were always assumed to be of type
`BorderRadiusStyleValue`, which could lead to a crash when CSS-wide
keywords were used.
This improves the output of `getComputedStyle()` for the `top`,
`bottom`, `left` and `right` properties, where the used value is now
returned rather than the computed value, where applicable."
We now parse `<counter-name>` values as a `<custom-ident>`. This
disallows `default` and CSS-wide keywords as counter names. The
specification additionally disallows `none` as a counter name.
At computed-value time, this is converted to whatever the parent's
computed value is. So it behaves a little like `inherit`, except that
an inherited start/end value uses the parent's start/end, which might
be different from the child's.
The Web::CSS::Parser's GradientParsing ignores color-stops if
it is only a single one. This change allows to have color-stops
with double positions against a single color.
Further, also allows for `linear-gradient(black)` and similar
other gradient functions
