Bug 179942

Summary: cross-fade(...) grammar/parsing does not match latest spec
Product: WebKit Reporter: Fredrik Söderquist <fs>
Component: ImagesAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: cnardi, jonlee, simon.fraser, webkit-bug-importer
Priority: P2 Keywords: FromImplementor, InRadar, WebExposed
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
URL: https://drafts.csswg.org/css-images/#cross-fade-function

Description Fredrik Söderquist 2017-11-22 05:31:21 PST
Copied from https://bugs.webkit.org/show_bug.cgi?id=157632#c3 :
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Webkit implementation of the grammar and the latest spec are not the same.

cross-fade() = cross-fade( <cf-mixing-image> , <cf-final-image>? )
<cf-mixing-image> = <percentage>? && <image>
<cf-final-image> = <image> | <color>

So we have to put the percentage in front of it, and remove the comma.

Before:
-webkit-cross-fade(url(foo.png), url(bar.png), 20%)

After:
cross-fade(20% url(foo.png), url(bar.png))
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If WontFixing this, then please consider raising an issue with the spec to change to the currently implemented grammar.
Comment 1 Radar WebKit Bug Importer 2017-11-27 12:59:08 PST
<rdar://problem/35705284>
Comment 2 Chris Nardi 2018-01-28 12:55:00 PST
I raised a spec issue for this at https://github.com/w3c/csswg-drafts/issues/2234.