While trying to repro bug 1484293 I noticed that this assertion failed: https://searchfox.org/mozilla-central/rev/ef8b3886cb173d5534b954b6fb7eb2d94a9473d0/dom/base/ShadowRoot.cpp#160 (during unlink, while unbinding the kids) We rely on GetComposedDoc returning the right thing during unbind to cleanup some stuff (see bug 1473637 for example), so it should probably be correct all the time, regardless of whether something is unlinked or not. Also this makes GetComposedDoc() much faster, which is nice too, since we call it somewhat often. I removed NodeHasRelevantHoverRules, since it's unused (was used by the old style system). I moved the SetIsConnected(false) call for the shadow root to before unbinding the kids for consistency with what Element does with the uncomposed doc flag, now that the children's connectedness doesn't depend on the shadow root's.

Comment on attachment 9002246 [details] Use a node bit for connectedness. Olli Pettay [:smaug] has approved the revision.

Pushed by emilio@crisal.io: https://hg.mozilla.org/integration/autoland/rev/39f61de4e7bb Use a node bit for connectedness. r=smaug

Backed out changeset 39f61de4e7bb (Bug 1484478) for bustages in /builds/worker/workspace/build/src/dom/base/ShadowRoot.cpp:526:20 Problematic push: https://treeherder.mozilla.org/#/jobs?repo=autoland&revision=39f61de4e7bb164f1ad812852b4f46bd18e3d96d&filter-resultStatus=testfailed&filter-resultStatus=busted&filter-resultStatus=exception&filter-classifiedState=unclassified Failure: https://treeherder.mozilla.org/#/jobs?repo=autoland&filter-resultStatus=testfailed&filter-resultStatus=busted&filter-resultStatus=exception&filter-classifiedState=unclassified&selectedJob=194819789 Failure log: https://treeherder.mozilla.org/logviewer.html#?job_id=194819789&repo=autoland&lineNumber=18616 [task 2018-08-20T11:13:10.107Z] 11:13:10 INFO - /builds/worker/workspace/build/src/dom/base/ShadowRoot.cpp:526:20: error: unused variable 'doc' [-Werror=unused-variable] [task 2018-08-20T11:13:10.107Z] 11:13:10 INFO - if (nsIDocument* doc = GetComposedDoc()) { [task 2018-08-20T11:13:10.108Z] 11:13:10 INFO - ^~~ [task 2018-08-20T11:13:10.108Z] 11:13:10 INFO - cc1plus: all warnings being treated as errors [task 2018-08-20T11:13:10.108Z] 11:13:10 INFO - /builds/worker/workspace/build/src/config/rules.mk:1088: recipe for target 'Unified_cpp_dom_base4.o' failed [task 2018-08-20T11:13:10.108Z] 11:13:10 INFO - make[4]: *** [Unified_cpp_dom_base4.o] Error 1 [task 2018-08-20T11:13:10.108Z] 11:13:10 INFO - make[4]: Leaving directory '/builds/worker/workspace/build/src/obj-firefox/dom/base' [task 2018-08-20T11:13:10.108Z] 11:13:10 INFO - make[4]: *** Waiting for unfinished jobs....

Backout by shindli@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/fb70309402b4 Backed out changeset 39f61de4e7bb for bustages in /builds/worker/workspace/build/src/dom/base/ShadowRoot.cpp:526:20

Pushed by emilio@crisal.io: https://hg.mozilla.org/integration/autoland/rev/31ed81aa4f46 Use a node bit for connectedness. r=smaug