On platinenmacher.tech there is a document without a window. During
size attribute parsing the window pointer is dereferenced which
causes a crash. This checks for the window to be actually there
before dereferencing.
As the spec points out:
> Note that a pair of keywords can be reordered while a combination of
> keyword and length or percentage cannot. So center left is valid while
> 50% left is not.
This was a bug in our implementation of alternative 2 of css-values-3,
resulting in the following CSS failing to be parsed:
`background-position: center right;`
This commit fixes the issue as part of an update of the parsing to
css-values-4. As far as I can tell, the grammar is equivalent - but
simpler to implement due to the lack of optional values.
The fix for this issue is also as part of alternative 2 parsing in the
new grammar.
Progress towards: #22401
Instead of serializing two calc() values to String and then comparing
those strings, we can now compare calc() values by actually traversing
their internal CalculationNode tree.
This makes style recomputation faster on pages with lots of calc()
values since it's now much cheaper to check whether a property with
some calc() value actually changed.
Before this change, parsed grid-template-columns/grid-template-rows
were represented as two lists: line names and track sizes. The problem
with this approach is that it erases the relationship between tracks
and their names, which results in unnecessarily complicated code that
restores this data (incorrectly if repeat() is involved) during layout.
This change solves that by representing line definitions as a list of
sizes and names in the order they were defined.
Visual progression https://genius.com/
Frequently we want to parse "anything that's a `<length-percentage>`" or
similar, which could be a constant value or a calculation, but didn't
have a nice way of doing so. That meant repeating the same "try and
parse a dimension, see if it's the right type, then maybe try and parse
a calculation and see if that's the right type" boilerplate code. Or
more often, forgetting about calculations entirely.
These helpers should make that a lot more convenient to do. And they
also use TokenStream, so we can eventually drop the old `parse_length()`
method.
We don't need to skip whitespace at the top level because that's already
done before we're called. But we do still have to skip it inside the
`add()` function
No functional impact intended. This is just a more complicated way of
writing what we have now.
The goal of this commit is so that we are able to store the 'name' of a
pseudo element for use in serializing 'unknown -webkit-
pseudo-elements', see:
https://www.w3.org/TR/selectors-4/#compat
This is quite awkward, as in pretty much all cases just the selector
type enum is enough, but we will need to cache the name for serializing
these unknown selectors. I can't figure out any reason why we would need
this name anywhere else in the engine, so pretty much everywhere is
still just passing around this raw enum. But this change will allow us
to easily store the name inside of this new struct for when it is needed
for serialization, once those webkit unknown elements are supported by
our engine.
