1191155 - flex-basis percent values should be resolved (instead of treated as 'auto') in quirks mode

Status: VERIFIED INVALID

(Core :: Layout, defect)

Description

[Daniel Holbert [:dholbert]]

Attachment: testcase 1

STR:
 1. Load attached testcase

EXPECTED RESULTS:
 No red visible.

ACTUAL RESULTS:
 Red is visible.

The testcase is in quirks mode (because there's no !DOCTYPE), so vertical percent values should be resolved (not treated as 'auto') in an auto-height container. See upcoming reference case w/ block layout instead of flex layout.

(This bug is the "separately, it looks like Firefox does not..." parenthetical mentioned at the end of this www-style post from biesi:
 https://lists.w3.org/Archives/Public/www-style/2015Aug/0027.html
)

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: testcase 1

[er, tweaking prose in testcase to just say "element" instead of "flex item", so the reference case (with no flex stuff) can use the same language without confusion]

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: reference case 1

Comment 3

[Boris Zbarsky [:bzbarsky]]

> vertical percent values should be resolved (not treated as 'auto') in an auto-height
> container

Should they?  The quirk at https://quirks.spec.whatwg.org/#the-percentage-height-calculation-quirk is restricted to percentage values of the 'height' property only, and I don't think we should be randomly extending it to other situations.

Comment 4

[Daniel Holbert [:dholbert]]

Yeah, let's leave this as-is. Our current behavior (on the testcase) is interoperable with Blink, and there's no compelling reason to add/extend quirks in a direction away from compatibility.

Comment 5

[Christian :Biesinger (don't email me, ping me on IRC)]

Yeah, I think we changed our (blink's) behavior since that mailing list post in comment 0, and I've come around to the view that quirks mode should not affect this.