1802744 - css atan2() should support like 'atan2(10px, 10vh)'

Status: NEW

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

Description

[Seokho Song]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.36

Steps to reproduce:

According to the code review on chromium[1], the WPT test case is wrong:

test_invalid_angle('atan2(90px, 90vw)');
test_invalid_angle('atan2(90px, 90em)');

I think the test is wrong. The spec just says y and x must be of the same type without saying anything about units [2]. Also I don't get what it means by "different dimensions" here.

[1] https://chromium-review.googlesource.com/c/chromium/src/+/4004379/comment/e6e45b6a_df4df8b7/
[2] https://drafts.csswg.org/css-values-4/#funcdef-atan2

Actual results:

Passed the invalid cases.

Expected results:

Gecko may need to change the implementation.

Comment 1

[David Shin[:dshin]]

As per the definition of type - yeah, both are length types, and so it seems that the calculation should be valid.

Comment 2

[Emilio Cobos Álvarez (:emilio)]

Yeah, so I took a closer look and I think it would be useful to restrict this to same units.

Otherwise we start hitting weird dependencies between properties that aren't supposed to have dependencies, like any non-length property starting to depend on font-sizes via em units... https://bugs.chromium.org/p/chromium/issues/detail?id=1392594 is basically the same issue.