This allows for two-location color stops (`color x% y%`) which is shorthand
for `color x%, color y%` where both colors are equal. (pct/length accepted)
See code comment for the reason it's implemented the way it is.
Resolves#2720
This also adds a new helper method for checking the type of tokens that will be parsed after the current token, which is useful for determining the unit of values inside calc() functions.
Partially based on 8a0897d23f
Pseudo-classes with a forgiving selector list argument are allowed to follow a pseudo-element, but must treat any selector that is not of the same type as invalid. It doesn't make any sense, but that's the behavior of other tainted browsers.
- Block slot elements from being matched by ::slotted
- Ensure ::slotted() is serialized as a pseudo-element
- Add pref to control whether the pseudo-class is enabled
What happens here if aListHead is an empty selector list:
(1) next selector group is parsed and continues to the next iteration if it's empty or invalid
(2) if we're a forgiving selector list and aListHead is empty, replace it with the selector group that we've just parsed
(3) step 1 ignores invalid/empty, so we assert that step 2 should never have an empty selector list
This modifies selector list parsing to accommodate being "forgiving". Aliases for the :is selector's former names were also included. Note that the older and prefixed variant `-moz-any` remains unforgiving.
I could have done this through a CSSLoader to allow all CSS unit quirks but
I wasn't planning to start passing around document and element references
everywhere, so instead just did it manually by accepting numbers/floats in
addition to pixel and percent.
This attempts to get the first non-whitespace token, which if exists, continues with previous behavior of parsing the margin string. Otherwise, if the specified margin string is empty or consists only of whitespace characters, is interpreted as zero length.
IntersectionObserver is the only consumer of the `ParseMarginString` method, as far as I can tell, so this should not affect anything else.
Note: For some reason, Firefox and Chrome treat the unitless zero length as invalid, while with this change, we do not change existing behavior in that regard and continue to accept that value.
This removes the `grid` prefix from the gap-related properties of grid since they are now part of the box alignment specification. Former grid-gap* properties were aliased to the unprefixed properties to maintain compatibility.
The previously multi-column layout only `column-gap` property has been modified to apply to the Grid layout (and Flexbox in a following commit), moving the `mColumnGap` member variable from `nsStyleColumn` to `nsStylePosition`.
Notes:
* Bug 1398537 - support for percent values in column-gap for multi-column layout landed as part of Issue #1230. However, it was incomplete because it did not update `nsRuleNode` to allow transformation of percentage values for `column-gap`. This was consequently fixed as part of this commit.
* Bug 1456166 - this might not apply because we don't have that devtools test in UXP
* `nsRuleNode`, `nsCSSParser`, `Declaration`, and other related classes were merged into Stylo. These should be taken into consideration when porting patches from Mozilla.
Partially based on https://bugzilla.mozilla.org/show_bug.cgi?id=1398482
