1518049 - Twitter embedded videos don't show TP shield when failing to load in Slack

Status: NEW

(Firefox :: Protections UI, defect, P3)

Description

[Adam Stevenson [:adamopenweb]]

Attachment: slackbug.png

Steps to reproduce:
1. Enable tracking protection basic list
2. Navigate to https://mozilla.slack.com/ (or other instance) and login
3. Paste a Twitter video link into a channel or a Direct Message(https://twitter.com/arlenparsa/status/1060228709850980354)
4. Click the play button

Expected result:
Video fails to load due to TP and shield icon appears

Actual result:
Video fails to load and no shield icon indicating what happened

In the console we see:
The resource at "https://video.twimg.com/ext_tw_video/1060228325178859520/pu/vid/958x496/WvlVX-v6xB3_smRY.mp4?tag=5" was blocked because content blocking is enabled

This possibly happens in other scenarios other than on Slack.

Comment 1

[Johann Hofmann [:johannh]]

Looking at this again this may be less relevant to our recent work than I immediately thought, assuming this is not a recent regression. There are other bugs where we miss to show the shield (e.g. bug 1451307) in some situations, it's not great but there are these edge cases. We should set up a meta bug for tracking it.

Comment 2

[Vlad Lucaci, Desktop QA (:vlucaci)]

Hello

I tried to pull a regression range many times and got the following two pushlogs every time:

https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=f82d56c64966a27cd87ab53025ebc774936b3657&tochange=d509647cc1d7589c1ccfd50340851362e1305c99

and

https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=db78be8dbc1c81844eb7d35c1a3073078eb5d923&tochange=443ff1adf8abe46d484d1b18c30bbd3ff007f640

I am not quite certain which issue is causing this, but bare in mind that Tracking Protection is no longer present.

Content blocking took its place instead, and with it, you can still reproduce this issue, if you set it to the Strict list.

Hope it helps.