Bug 167699 – Serialization of custom props in longhand should be "" not value of shorthand

• Component: CSS
• Status: RESOLVED FIXED

[Greg Whitworth]

Example URL:
https://jsfiddle.net/ok8uwunf/

Steps to reproduce the problem:
1. Open https://jsfiddle.net/ok8uwunf/
2. Look at value displayed in target element

What is the expected behavior?
================================
The value should be "" since the variable substitution hasn't occurred

What went wrong?
================================
It seems that Blink doesn't follow this line of the spec:

"Pending-substitution values must be serialized as the empty string, if an API allows them to be observed."

Since we are looking at specified style, this needs to be an empty string.

Firefox: no repro
Edge: no repro
Blink: Repro

[Radar WebKit Bug Importer]

<rdar://problem/30324200>

[Dean Jackson]

Created attachment 305329 [details]
Patch

[Sam Weinig]

Comment on attachment 305329 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=305329&action=review

> LayoutTests/fast/css/variables/rule-property-get.html:9
> +/* https://www.w3.org/TR/css-variables/#variables-in-shorthands
> +   "Pending-substitution values must be serialized as the empty string, if an API allows them to be observed." */

I think this comment could use some context, explaining what the test is testing.

[Dean Jackson]

Committed r214383: <http://trac.webkit.org/changeset/214383>