1413119 - Fix stylo-only failure of shadow DOM web platform test shadow-dom/untriaged/styles/test-005.html

Status: RESOLVED FIXED

(Core :: DOM: CSS Object Model, defect, P3)

Description

[Ben Tian (inactive)]

The following web platform test fails in stylo only
https://w3c-test.org/shadow-dom/untriaged/styles/test-005.html

with error message:

assert_equals: CSS styles declared in shadow tree must be applied to the element in the same shadow tree expected 0 but got 27

@https://w3c-test.org/shadow-dom/untriaged/styles/test-005.html:56:5
unit/<@https://w3c-test.org/shadow-dom/resources/shadow-dom-utils.js:66:13
Test.prototype.step@https://w3c-test.org/resources/testharness.js:1489:20
test@https://w3c-test.org/resources/testharness.js:511:9
@https://w3c-test.org/shadow-dom/untriaged/styles/test-005.html:26:1

--

Note pref "dom.webcomponents.enabled" as true is required to run the above test.

Comment 1

[Emilio Cobos Álvarez (:emilio)]

So the reason this is failing is because of:

  http://searchfox.org/mozilla-central/rev/1c4901d060e3953e41088c038b62a0c026c1e1fb/dom/xbl/nsXBLPrototypeResources.cpp#119

`shell` is null there, because it's a non-rendered (yet) iframe.

Indeed tweaking the test like:

diff --git a/shadow-dom/untriaged/styles/test-005.html b/shadow-dom/untriaged/styles/test-005.html
index 0debdec5fc..aa10fc50ee 100644
--- a/shadow-dom/untriaged/styles/test-005.html
+++ b/shadow-dom/untriaged/styles/test-005.html
@@ -38,6 +38,8 @@ test(unit(function (ctx) {
     //Shadow root to play with
     var s = host.attachShadow({mode: 'open'});
 
+    d.body.offsetTop;
+
     var style = d.createElement('style');
     style.innerHTML ='.invis {display:none}';
     s.appendChild(style);

Makes it pass.

Now, the deeper issue here is what should happen when shadow roots are in a non-rendered document (in the sense of, what do media queries evaluate to, and such)...

Comment 2

[Chris Peterson [:cpeterson]]

status-firefox57=wontfix unless someone thinks this bug should block 57

Comment 3

[Emilio Cobos Álvarez (:emilio)]

I fixed this a while ago.