784461 - change how CSS property aliases are stored for transition-property

Status: NEW

(Core :: CSS Parsing and Computation, defect)

Description

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

The CSS working group agreed at our meeting last week in San Diego that the general mechanism for any property aliasing that we need to do involves treating aliases like shorthands that are for a single property (since we already have an underlying model there).

Our lightweight implementation of aliases matches this in all but one respect, I believe (modulo underspecified bits of the CSSOM where it's fine in reality but may not match the inaccurate letter of the current spec):  the serialization of values of transition-property.

We should change the way we store values of transition-property so that we serialize aliases as-is rather than converting them to what they alias.

Comment 1

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

I have some work-in-progress on this in https://hg.mozilla.org/users/dbaron_mozilla.com/patches/ , which I started for a different bug, but am putting aside for now.

Comment 2

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

I moved the first 4 of the 6 patches I have into bug 849656.