1297007 - Switching to a Youtube tab with "media.block-play-until-visible" set to 1 makes the video replay if playback completed while the tab was inactive

Status: RESOLVED DUPLICATE of bug 1262053

(Core :: Audio/Video: Playback, defect, P3)

Description

[override.dll]

User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:50.0) Gecko/20100101 Firefox/50.0
Build ID: 20160819004015

Steps to reproduce:

1. Set "media.block-play-until-visible" to true with about:config or user.js
2. Open any Youtube video and let it start playing automatically (for example, https://www.youtube.com/watch?v=hS5CfP8n_js )
3. Switch to another tab before the video ends
4. Wait for it to end
5. Switch to the tab


Actual results:

Upon switching to the tab in step 5, video playback starts again. I reproduced this behavior in Firefox Developer Edition 50.0a2 (2016-08-19) with a new profile.


Expected results:

It shouldn't start again.

Comment 1

[Tooru Fujisawa [:arai]]

Confirmed on Nightly 2016-08-21 on OSX.

Comment 2

[Alastor Wu [:alwu]]

We would use new mechanism to manage blocking autoplay video in bug1262053.
In addition, it's correct behavior if the tab starts playing again after step 5.