alexandr.spy Reporter
	Description • 6 years ago

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:60.0) Gecko/20100101 Firefox/60.0
Build ID: 20180605171542

Steps to reproduce:

Take a tab with vieo player in it,make new window out of the tab then make it a tab again (must be a tab in the window in which created) and press fullscreen button



Actual results:

Video players (youtube, twitch ,stormo player) cannot go fullscreen 
Reload page doesn't help
Going to other site and coming back helps
Other video players work just fine


Expected results:

Video should've went fullscreen

	Alice0775 White
	Comment 1 • 6 years ago

I can confirm that the problem is reproduced on Win10 Nightly62.0a1 and Firefox60, but not on ESR52.

Error in Browser Console(Firefox60):
NS_ERROR_NOT_AVAILABLE:   videocontrols.xml:391
Request for fullscreen was denied because requesting element is not in the currently focused tab.  foobar.mp4

	Alice0775 White
	Comment 2 • 6 years ago

Regression window:
https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=fab7bacb59284801d9c47f6ef5d0529f5ae20154&tochange=9e59ca9dd30d73c57dad6a7e6220b159dd1e6db5

Regressed by:d64ad536c158	Florian Quèze — Bug 1391704 - Avoid flickering while moving tabs across windows, r=mconley.

	Xidorn Quan [:xidorn] UTC+11
	Comment 3 • 6 years ago

The error message shown in console is FullscreenDeniedNotFocusedTab, which means it fails IsInActiveTab check[1], so the reason is somehow we don't set active state to either the docshell or the window.

Switching tab / window or even just changing focus to other chrome element seems to help this.


[1] https://searchfox.org/mozilla-central/rev/93d2b9860b3d341258c7c5dcd4e278dea544432b/dom/base/nsDocument.cpp#10956

	Florian Quèze [:florian]
	Comment 4 • 6 years ago

(In reply to Xidorn Quan [:xidorn] UTC+10 from comment #3)

So likely the same root cause as bug 1459327 and bug 1467206.

	Liz Henry (:lizzard Please n-i to RyanVM, jcristau, or pascal)
	Comment 5 • 6 years ago

Edge case, so dropping this from weekly triage. We could still take a patch for 63 or even 62.

	Liz Henry (:lizzard Please n-i to RyanVM, jcristau, or pascal)
	Comment 6 • 6 years ago

Happy to take a patch in nightly; if it seems low risk enough please feel free to request uplift to 65 beta.