1516821 - Computed value of word-spacing with calc(percentage) is incorrect

Status: RESOLVED WORKSFORME

(Core :: CSS Parsing and Computation, defect, P3)

Description

[Gérard Talbot]

Reduced test
- - - - - - 

http://www.gtalbot.org/BrowserBugsSection/CSS3Values/Bugzilla-getComputedStyle-word-spacing.html



Actual result: 3 sub-test failures
eg: the reported computed value of 'word-spacing: calc(25%)' is '0px + 25%'


Expected result: 3 sub-test successes
eg: the reported computed value of 'word-spacing: calc(25%)' should be the fallback value which was arbitrary set to 8px in the 3 sub-tests.

word-spacing does not accept percentage unit. So, the computed value should be the one from its fallback value.


Notes
-----
- The original test is:
https://chromium.googlesource.com/chromium/src/+/c825d655f6aaf73484f9d56e9012793f5b9668cc/third_party/WebKit/LayoutTests/css3/calc/word-spacing.html
In this original test, the fallback value has been set to 20px
- I get actual results with Firefox 60.4.0 ESR and with Firefox 66.0a1 buildID=20181229093614
- Chromium 71.0.3578.80 pass this test
- I searched for a duplicate and did not find any.

Comment 1

[Gérard Talbot]

> - The original test is:
> https://chromium.googlesource.com/chromium/src/+/
> c825d655f6aaf73484f9d56e9012793f5b9668cc/third_party/WebKit/LayoutTests/css3/
> calc/word-spacing.html

I copied such test here:

http://www.gtalbot.org/BrowserBugsSection/CSS3Values/chromium-word-spacing.html

> In this original test, the fallback value has been set to 20px

Comment 2

[Xidorn Quan [:xidorn] UTC+11]

So percentage value of word-spacing was initially added for w3c/csswg-drafts#2165 and later removed in https://github.com/w3c/csswg-drafts/commit/70e11db3dcc0fda5cc0ee89be5bd347477d565c2.

It's not very clear to me what's the plan here...

fantasai, could you clarify what's the plan for percentage value of word-spacing?

Comment 3

[Gérard Talbot]

I have added related /csswg-drafts/issues/ comments into the test.

[css-text-3] Remove percentage word-spacing in preparation for redefining it
https://github.com/w3c/csswg-drafts/commit/70e11db3dcc0fda5cc0ee89be5bd347477d565c2
December 7th 2018

So, I am putting the related tests in my to-revisit-later stack.

Comment 4

[fantasai]

I removed percentage word-spacing in response to https://github.com/w3c/csswg-drafts/issues/2165 where we resolved to add percentages to a number of text layout features to represent percentages of the font-size. That definition would be incompatible with making percentages represent the advance of each word separator character. We'd also like to have such a value, but not sure yet what's a good way to represent it... numbers would have been ideal (they'd be compatible with tab-size), but there's issues with numbers in calc(), so I don't have a good answer atm.

Comment 5

[Gérard Talbot]

Then I am resolving this bug report. I'll create a new one when the spec is settled and if Firefox fails related+relevant tests.

Resolving as WORKSFORME