+++ This bug was initially created as a clone of Bug #1467179 +++ I got a ghost window on engadget that looks a lot like this bug 1467179. I guess the fix there did not really address the issue. bkelly@valen:/mnt/c/devel/tmp/cclogs$ /srv/heapgraph/find_roots.py cc-edges.12472.1530023738.log 000 002AAC137C000 Parsing cc-edges.12472.1530023738.log. Done loading graph. 000002AAA2512A00 [MessagePort https://www.youtube.com/embed/pzBDhnWK6zg?enablejsapi=1] --[mListenerManager]--> 000002AAA17CE5E0 [EventListenerManager] --[mListeners event=onmessage listenerType=2 [i]]--> 000002AAD07EB4F0 [JSEventHandler handlerNam e=onmessage] --[mTypedHandler.Ptr()]--> 000002AAC8004640 [CallbackObject] --[mIncumbentGlobal]--> 000002AAA1556800 [nsGlobalWindowInner # 2147489984 inner https://www.you tube.com/embed/pzBDhnWK6zg?enablejsapi=1] --[mTopInnerWindow]--> 000002AA96E19000 [nsGlobalWindowInner # 2147489960 inner https://www.enga dget.com/2018/06/22/babylon-5-digital-video-quality/] --[mDoc]--> 000002AA8202F800 [nsDocument normal (xhtml) https://www.engadget.com/2018/06/22/baby lon-5-digital-video-quality/] --[mListenerManager]--> 000002AA8BDC18B0 [EventListenerManager] --[mListeners event=onwebdriver-evaluate-response listenerType=3 [i]]--> 000002AADFD92310 [CallbackObject] --[mIncumbentGlobal]--> 000002AA9BB03800 [nsGlobalWindowInner # 2147490082 inner https://www.engadget.com/2018/06/22/babylon-5-digital-video-quality/] --[mDoc]--> 000002AAA170E800 [nsDocument normal (xhtml) https://www.engadget.com/2018/06/22/babylon-5-digital-video-quality/] --[mChildren[i]]--> 000002AAA22AEB00 [FragmentOrElement (xhtml) html https://www.engadget.com/2018/06/22/babylon-5-digital-video-quality/] --[mAttrsAndChildren[i]]--> 000002AAA261BE80 [FragmentOrElement (xhtml) body https://www.engadget.com/2018/06/22/babylon-5-digital-video-quality/] --[]--> 000002AAC28CCB80 [nsDOMMutationObserver] --[mCallback]--> 000002AACF2FBDF0 [CallbackObject] --[mCallback]--> 000002AAC58F4EC0 [JS Object (Function - gd/c<)] --[fun_environment]--> 000002AAE2FF09A0 [JS Object (Call)] --[enclosing_environment]--> 000002AACE934E20 [JS Object (Call)] --[l]--> 000002AAD8BBE280 [JS Object (Object)] --[request]--> 000002AAC58F3040 [JS Object (Function - request)] --[fun_environment]--> 000002AAC5862BC0 [JS Object (Call)] --[g]--> 000002AAD4E75CA0 [JS Object (Object)] --[mobileApp]--> 000002AAC584D4C0 [JS Object (Function - instantiateModules/<)] --[fun_environment]--> 000002AAC584F1C0 [JS Object (Call)] --[q]--> 000002AAC182B7C0 [JS Object (Object)] --[mAdTalk]--> 000002AAD93B72E0 [JS Object (Object)] --[getFrameMapIncludingPeerCase]--> 000002AAC5819680 [JS Object (Function - getFrameMapIncludingPeerCase)] --[fun_environment]--> 000002AAC582F380 [JS Object (Call)] --[u]--> 000002AAD93B71C0 [JS Object (Object)] --[list]--> 000002AACCC61430 [JS Object (Array)] --[objectElements[41]]--> 000002AAD7C1F200 [JS Object (Object)] --[isValidForMapping]--> 000002AAC583DB40 [JS Object (Function - isValidForMapping)] --[fun_environment]--> 000002AAC584E160 [JS Object (Call)] --[a]--> 000002AAE4015540 [JS Object (Proxy)] --[proxy target]--> 000002AAA12BE240 [JS Object (Proxy)] --[group_global, proxy target]--> 000002AAC2732A60 [JS Object (Window)] --[UnwrapDOMObject(obj)]--> 000002AAA110B000 [nsGlobalWindowInner # 2147490091 inner https://www.engadget.com/2018/06/22/babylon-5-digital-video-quality/] --[mDoc]--> 000002AADD50B000 [nsDocument normal (xhtml) https://www.engadget.com/2018/06/22/babylon-5-digital-video-quality/] --[mReadyForIdle]--> 000002AAD0B4ED60 [Promise] --[mGlobal]--> 000002AAC137C000 [nsGlobalWindowInner # 2147490090 inner https://www.engadget.com/2018/06/22/babylon-5-digital-video-quality/] Root 000002AAA2512A00 is a ref counted object with 1 unknown edge(s). known edges: 000002AABF569340 [MessagePort https://www.youtube.com/embed/pzBDhnWK6zg?enablejsapi=1] --[mUnshippedEntangledPort]--> 000002AAA2512A00 000002AAA47A4F00 [MessageChannel] --[mPort1]--> 000002AAA2512A00

This leak is from 62.0a1 (2018-06-19) (64-bit). Thats after bug 1467179 shipped in nightly afaict.

No. When I tried to reproduce I commented on the bug when I saw the detached window. It did not become a ghost that time. My comment 0 leak was a different session where the window was a day old and definitely a ghost.

Without STR, I'm going to mark this incomplete.