Bug 187244 – [cairo] Doesn't paint box-shadow with zero blur-radius

• Status: RESOLVED
• Resolution: FIXED
• Component: WebKitGTK

[Fujii Hironori]

Created attachment 344086 [details]
current GTK's inset-expected.png failing to draw some box-shadow

[cairo] Doesn't paint box-shadow with zero blur-radius

fast/box-shadow/inset.html is the test case.

[Fujii Hironori]

Created attachment 344087 [details]
WIP patch

[Fujii Hironori]

Created attachment 344088 [details]
inset-expected.png after this change

[Fujii Hironori]

This is the screenshot of the important blog for WebKitGTK+ after this fix :-)
https://photos.app.goo.gl/87b64JeZhJ1GDK2N7

[Zan Dobersek]

(In reply to Fujii Hironori from comment #1)
> Created attachment 344087 [details]
> WIP patch

LGTM, but please make it reviewable.

[Michael Catanzaro]

Thanks for fixing my blog!

[Michael Catanzaro]

Comment on attachment 344087 [details]
WIP patch

View in context: https://bugs.webkit.org/attachment.cgi?id=344087&action=review

BTW, I'm really curious how you managed to debug this issue.

> Source/WebCore/platform/graphics/cairo/CairoOperations.cpp:616
>      // We can't avoid ShadowBlur if the shadow has blur.
> -    if (color.isVisible() && blur)
> +    if (color.isVisible())

The comment needs to be updated now.

[Fujii Hironori]

(In reply to Michael Catanzaro from comment #6)
> 
> BTW, I'm really curious how you managed to debug this issue.

I was just lucky. I was grepping "blur" and found the suspicious condition.

[Fujii Hironori]

Created attachment 344169 [details]
Patch

[Fujii Hironori]

Comment on attachment 344169 [details]
Patch

Clearing flags on attachment: 344169

Committed r233495: <https://trac.webkit.org/changeset/233495>

[Fujii Hironori]

All reviewed patches have been landed.  Closing bug.

[Fujii Hironori]

It turned out this is not a right fix.
I filed bug 187336.