1841638 - scale() does not serialize single NaN value correctly

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, defect)

Description

[Oliver Medhurst [:canadahonk]]

Serializes as scale(calc(NaN), calc(NaN)) instead of scale(calc(NaN)) (repeated values should not be used). This issue may also pop up in (many) other places as x == y is not true if both values are NaN (due to IEEE 754 floating point spec).

WPT tests:
See end of subtests here failing with incorrect value scale(calc(NaN), calc(NaN)):

• https://wpt.fyi/results/css/css-values/sin-cos-tan-serialize.html
• https://wpt.fyi/results/css/css-values/round-mod-rem-serialize.html

Comment 1

[Oliver Medhurst [:canadahonk]]

Attachment: Bug 1841638 - Fix scale() single NaN value serialization

Added custom implementation of PartialEq for Numbers to also check if
they are both NaN values.

WPT tests not specifically for this but incorrect serialization of
expected results:

• https://wpt.fyi/results/css/css-values/round-mod-rem-serialize.html
• https://wpt.fyi/results/css/css-values/sin-cos-tan-serialize.html

15 WPT subtests now newly pass :tada:

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e3f62ea4e593
Fix scale() single NaN value serialization r=emilio

Comment 3

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/e3f62ea4e593