1512026 - Nested slot doesn't match ::slotted against the right tree

Status: VERIFIED FIXED

(Core :: CSS Parsing and Computation, defect)

Description

[kendrick.caranicas]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.110 Safari/537.36

Steps to reproduce:

Create 2 web components. Using slots have the Parent pass a slotted node into the child  slot. The child should have styles specific to the what container the slot is within. 

Here is a link to glitch that demos this. It works properly in chrome and safari.  
https://firefox-nested-slot.glitch.me/


Actual results:

None of the specific styles are displayed on the page or in the inspector. 


Expected results:

I should see the styles for the various slotted components based on their selector chain.

Comment 1

[ovidiu boca[:Ovidiu]]

I tested this issue on Mac OS X 10.14 and Windows 10 x64 with FF Nightly 65.0a1(2018-12-09) and FF 63 release and I can reproduce the issue.

Comment 2

[Emilio Cobos Álvarez (:emilio)]

I think I know what's going on, thanks for the report. FWIW a testcase without a bunch of unnecessary JS would help a lot to debug this.

I'll write one when I get to debug this.

Comment 3

[Emilio Cobos Álvarez (:emilio)]

Attachment: Reduced test-case.

Comment 4

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1512026 - Handle nested slots correctly in slotted matching and invalidation.

The patch and test should be pretty much self-descriptive.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/7b04cdcfdcf4
Handle nested slots correctly in slotted matching and invalidation. r=heycam

Comment 6

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream web-platform-tests status checks passed, PR will merge once commit reaches central.

Comment 7

[Bogdan Tara[:bogdan_tara | bogdant]]

https://hg.mozilla.org/mozilla-central/rev/7b04cdcfdcf4

Comment 8

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream PR merged

Comment 9

[Ryan VanderMeulen [:RyanVM]]

Is this something we should consider for Beta backport?

Comment 10

[Emilio Cobos Álvarez (:emilio)]

Comment on attachment 9030224 [details]
Bug 1512026 - Handle nested slots correctly in slotted matching and invalidation.

[Beta/Release Uplift Approval Request]

Feature/Bug causing the regression: Not a regression

User impact if declined: Interop issue when using Shadow DOM  / Web Components.

Is this code covered by automated tests?: Yes

Has the fix been verified in Nightly?: Yes

Needs manual test from QE?: Yes

If yes, steps to reproduce: See the test-case or the URL provided by the reporter.

List of other uplifts needed: none

Risk to taking this patch: Low

Why is the change risky/not risky? (and alternatives if risky): Relatively straight-forward correctness bug fix.

String changes made/needed: none

Comment 11

[Ryan VanderMeulen [:RyanVM]]

Comment on attachment 9030224 [details]
Bug 1512026 - Handle nested slots correctly in slotted matching and invalidation.

[Triage Comment]
Fixes an interop issue when using Shadow DOM & Web Components. Approved for 65.0b6.

Comment 12

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-beta/rev/da461fa0a394

Comment 13

[Emil Ghitta, QA [:emilghitta]]

I have managed to reproduce the issue described in comment 0 using Firefox 65.0b5.

This issue is verified fixed using Firefox 66.0a1 (BuildId:20181219220049) and Firefox 65.0b6 (provided in comment 12) on Windows 10 64bit, macOS 10.9 and Ubuntu 16.04 64bit.