Bug 139258 – dominant-baseline in an SVG <text> tag is not inherited by its children <tspan> tags

• Component: SVG
• Status: REOPENED

[Said Abou-Hallawa]

Open the following svg

<svg xmlns="http://www.w3.org/2000/svg">
  <line x1="0" y1="200" x2="100%" y2="200" style="stroke:rgb(255,0,0);stroke-width:1" />
  <text x="20" y="200" dominant-baseline="central" font-size="50px">
    foo<tspan>bar </tspan><tspan>baz</tspan>
  </text>
</svg>

Result: The first word "foo" is the only text which is rendered with alignment equal to "central". The rest of the text in the <tspan> tags is rendered with alignment equal to "alphabetic".

The w3c specs http://www.w3.org/TR/SVG/text.html says about the value "auto" of the dominant-baseline, which is the default: "If this property occurs on a ‘tspan’, ‘tref’, ‘altGlyph’ or ‘textPath’ element, then the dominant-baseline and the baseline-table components remain the same as those of the parent text content element."

So it is expected to have all the text in the <tspan> tags in the svg above to be rendered with the same alignment as the parent text content element's alignment.

[Said Abou-Hallawa]

Created attachment 242573 [details]
result

[Said Abou-Hallawa]

Created attachment 242574 [details]
expected

[Radar WebKit Bug Importer]

<rdar://problem/19144671>

[Yan Wong]

dominant-baseline should be inherited in SVG 2, so this is an SVG 2 improvement, which would be welcome in webkit. It *is* inherited in the latest version of Chrome and Firefox. See https://www.fxsitecompat.dev/en-CA/docs/2019/dominant-baseline-is-now-inherited-from-its-parent-element/

[Ahmad Saleem]

https://src.chromium.org/viewvc/blink?view=revision&revision=199970

^ This makes us pass following test case - https://jsfiddle.net/azLe745x/

but it regresses following:

imported/w3c/web-platform-tests/svg/styling/presentation-attributes-irrelevant.html
imported/w3c/web-platform-tests/svg/styling/presentation-attributes-relevant.html
imported/w3c/web-platform-tests/svg/styling/presentation-attributes-unknown.html

With following failing:

dominant-baseline presentation attribute supported on a irrelevant element
dominant-baseline presentation attribute supported on a relevant element
dominant-baseline presentation attribute supported on an unknown SVG element

[Ahmad Saleem]

(In reply to Ahmad Saleem from comment #5)
> https://src.chromium.org/viewvc/blink?view=revision&revision=199970
> 
> ^ This makes us pass following test case - https://jsfiddle.net/azLe745x/
> 
> but it regresses following:
> 
> imported/w3c/web-platform-tests/svg/styling/presentation-attributes-
> irrelevant.html
> imported/w3c/web-platform-tests/svg/styling/presentation-attributes-relevant.
> html
> imported/w3c/web-platform-tests/svg/styling/presentation-attributes-unknown.
> html
> 
> With following failing:
> 
> dominant-baseline presentation attribute supported on a irrelevant element
> dominant-baseline presentation attribute supported on a relevant element
> dominant-baseline presentation attribute supported on an unknown SVG element

Running these tests directly from WPT on Minibrowser where I have Blink patch merged does not show them failing when I do merge. :-(

I do have other SVG patches, which can mess with my internal build, so I think I can try doing draft PR.

Any suggestion?

[EWS]

Committed 265525@main (0ed9d940afc3): <https://commits.webkit.org/265525@main>

Reviewed commits have been landed. Closing PR #14833 and removing active labels.

[Ahmad Saleem]

*** Bug 249085 has been marked as a duplicate of this bug. ***

[Ahmad Saleem]

*** Bug 217564 has been marked as a duplicate of this bug. ***

[WebKit Commit Bot]

Re-opened since this is blocked by bug 259335