Instead of trying to locate the relevant StyleSheetList on style element
removal from the DOM, we now simply keep a pointer to the list instead.
This fixes an issue where using attachShadow() on an element that had
a declarative shadow DOM would cause any style elements present to use
the wrong StyleSheetList when removing themselves from the tree.
Before this change, removing a style element from inside a shadow tree
would cause it to be unregistered with the document-level list of sheets
instead of the shadow-root-level list.
This would eventually lead to a verification failure if someone tried to
update the text contents of that style element, since it was still in
the shadow-root-level list, but now with a null owner element.
Fixes a crash on https://www.swedbank.se/
Previously, the parent CSS stylesheet, owner node and owner CSS rule
properties were not unset when removing a sheet from a StyleSheetList.
This change moves the methods for adding and removing sheets to and
from a StyleSheetList, directly into the StyleSheetList class and
ensures they are called as required by the CSSOM specification.
If a style element belongs to a shadow tree, its CSSStyleSheet is now
added to the corresponding ShadowRoot instead of the document.
Co-authored-by: Simon Wanner <simon+git@skyrising.xyz>
This commit removes DeprecatedString's "null" state, and replaces all
its users with one of the following:
- A normal, empty DeprecatedString
- Optional<DeprecatedString>
Note that null states of DeprecatedFlyString/StringView/etc are *not*
affected by this commit. However, DeprecatedString::empty() is now
considered equal to a null StringView.
This should allow us to add a Element::attribute which returns an
Optional<String>. Eventually all callers should be ported to switch from
the DeprecatedString version, but in the meantime, this should allow us
to port some more IDL interfaces away from DeprecatedString.
Some websites (like Reddit) like to instantiate "components" by setting
innerHTML to a huge chunk of stuff. Sometimes those huge chunks of stuff
contain inline style sheets (i.e `<style>` elements).
Before this change, we would end up parsing the CSS in those elements
multiple times, because we had no way of knowing that we were within
a fragment parser's temporary document.
This patch avoids the extra CSS parsing work by adding adding a flag to
Document that tells us it's being used by the fragment parser. Then, we
simply avoid parsing CSS for style elements in such documents. The CSS
then gets parsed immediately upon insertion into the proper DOM.
