Bug 200211 – wpt/css/css-images/gradient/color-stops-parsing.html fails

• Status: RESOLVED
• Resolution: FIXED
• Component: CSS

[Simon Fraser (smfr)]

wpt/css/css-images/gradient/color-stops-parsing.html fails once the crash (bug 200206) is fixed.

[Simon Fraser (smfr)]

It fails on cases where there are multiple length values not separated by commas:

linear-gradient(black, 25% 50%, white)

Chrome and Firefox pass these tests. The relevant parsing code in Chrome is protected by RuntimeEnabledFeatures::MultipleColorStopPositionsEnabled() which was added via https://chromiumcodereview.appspot.com/2799793002/. I'm not sure if this is enabled by default in Chrome yet.

[Florin Malita]

This was shipped in Chrome m71: https://chromium-review.googlesource.com/c/chromium/src/+/1230018/

(see also https://chromestatus.com/feature/5712111258828800)

[Simon Fraser (smfr)]

Created attachment 375050 [details]
Patch

[Simon Fraser (smfr)]

Comment on attachment 375050 [details]
Patch

This breaks a conic gradient test.

[Simon Fraser (smfr)]

Created attachment 381563 [details]
Patch

[Simon Fraser (smfr)]

Created attachment 381601 [details]
Patch

[Said Abou-Hallawa]

Comment on attachment 381601 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=381601&action=review

> Source/WebCore/css/CSSGradientValue.cpp:123
> +        else if (i) {

Is it possible that i == 0 && stop.isMidpoint == true? I think it should not. If this is correct then I would suggest replacing else if (i) by ASSERT(i).

[Simon Fraser (smfr)]

(In reply to Said Abou-Hallawa from comment #7)
> Comment on attachment 381601 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=381601&action=review
> 
> > Source/WebCore/css/CSSGradientValue.cpp:123
> > +        else if (i) {
> 
> Is it possible that i == 0 && stop.isMidpoint == true? I think it should
> not. If this is correct then I would suggest replacing else if (i) by
> ASSERT(i).

I don't think you can get a mid-point stop before a colorless stop. I could add the assertion.

[Simon Fraser (smfr)]

https://trac.webkit.org/changeset/251474/webkit

[Radar WebKit Bug Importer]

<rdar://problem/56527169>