Tidy up check for zero-length lists when interpolating
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Address feedback from https://github.com/servo/servo/pull/17613#discussion_r125775874
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Before this refactoring, getComputedStyle could have side effects, and left the
style data in the element, so we could never arrive there without data.
There are a few crashtests that caught this, but this was already broken if you
called animate() on an element deep in a display: none subtree.
MozReview-Commit-ID: 1AvOvhAyOP3
This is unfortunate, but for now it complicates things, I would like not needing
a ElementData to get the style of an Element in order to fix all the
getDefaultComputedStyle bugs.
MozReview-Commit-ID: LZvsdFEqrDE
Implement paint worklet properties
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This is the final PR to get basic paint worklet support. It adds support for paint worklet properties (https://drafts.css-houdini.org/css-paint-api/#paint-definition-input-properties). When a paint worklet is registered, it specifies a list of CSS properties, and is provided with their computed values when it is invoked.
This is a dependent PR:
* "Implemented paint worklets invoking worklet scripts" is #17239.
* "Implemented paint worklets rendering contexts" is #17326.
There should be tests added for this, hopefully the existing wpt houdini tests.
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Make Servo's rounding of image-orientation values agree with Gecko's, and pass orientations directly as an enum instead of as angles.
Has been reviewed: https://reviewboard.mozilla.org/r/155336/
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Bugzilla issue: https://bugzilla.mozilla.org/show_bug.cgi?id=1355380
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selectors: Avoid looking at MatchingMode if the selector isn't the topmost.
Also, switch the hover quirk to the same mechanism.
Bug: 1379696
Reviewed-By: bholley
MozReview-Commit-ID: KrmNqNyASf6
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When a transition update is needed during restyling, `get_after_change_style` is
called to re-cascade without transition rules, and this style is then used for
primary styling instead of the style just computed.
`get_after_change_style` used to ignore visited styles, so this meant that if a
transition update was needed, visited styles were effectively dropped.
To fix the crash here, we pass through the existing visited styles when
re-cascading as part of `get_after_change_style`.
MozReview-Commit-ID: 4HBQAdeJ38B
People apparently do all sorts of silly stuff with stylesheets, see Google Inbox
in bug 1379203.
Bug: 1379433
Reviewed-By: heycam
MozReview-Commit-ID: 4x2d3glOFu8
This is only slightly more informative because it doesn't give
the filename, but I think it's an improvement on the simple
unwrap() panic when we try to read a file which isn't there.
See also [Gecko bug 1368083](https://bugzilla.mozilla.org/show_bug.cgi?id=1368083).
