Return 'none' as the computed style for mask when there are no images

[Matt Woodrow]

rdar://88178304

We currently always return the full set of properties for the computed style of mask, even when there aren't any images (which matches what we do for background).

To match other engines, we should just return 'none' for the case where there are no images.

[Matt Woodrow]

Created attachment 451161 [details]
Patch

[Matt Woodrow]

Created attachment 451193 [details]
Patch

[Matt Woodrow]

Created attachment 451210 [details]
Patch

[EWS]

Committed r289377 (246965@main): <https://commits.webkit.org/246965@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 451210 [details].

[Darin Adler]

Comment on attachment 451210 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=451210&action=review

> Source/WebCore/css/CSSComputedStyleDeclaration.h:99
> -    Ref<CSSValueList> getFillLayerPropertyShorthandValue(CSSPropertyID, const StylePropertyShorthand& propertiesBeforeSlashSeparator, const StylePropertyShorthand& propertiesAfterSlashSeparator, CSSPropertyID lastLayerProperty);
> -    Ref<CSSValueList> getBackgroundShorthandValue();
> -    Ref<CSSValueList> getMaskShorthandValue();
> +    RefPtr<CSSValue> getFillLayerPropertyShorthandValue(CSSPropertyID, const StylePropertyShorthand& propertiesBeforeSlashSeparator, const StylePropertyShorthand& propertiesAfterSlashSeparator, CSSPropertyID lastLayerProperty);
> +    RefPtr<CSSValue> getBackgroundShorthandValue();
> +    RefPtr<CSSValue> getMaskShorthandValue();

Why the change from Ref to RefPtr? These can’t return nullptr, can they?

[Matt Woodrow]

(In reply to Darin Adler from comment #5) 
> Why the change from Ref to RefPtr? These can’t return nullptr, can they?

Ah indeed, this is a remnant from an earlier revision of the patch, I could have left these as Ref.