Fetches to slack-imgs.com from app.slack.com appear in the logger, but not in the switcher

[FiloSottile]

Prerequisites

• [x] I performed a cursory search of the issue tracker to avoid opening a duplicate issue
  • Your issue may already be reported.
  • [x] I also searched the existing issues at https://github.com/gorhill/uMatrix/issues
• [x] This is not a support issue or a question
  • Support issues and questions are handled at /r/uMatrix
• I tried to reproduce the issue when...
  • [x] uMatrix is the only extension
  • [ ] uMatrix with default lists/settings
  • [ ] using a new, unmodified browser profile
• [x] I am running the latest version of uMatrix
• [x] I checked the documentation to understand that the issue I report is not a normal behavior
• [x] I used the logger to rule out that the issue is caused by my ruleset

Description

Fetches to slack-imgs.com from app.slack.com appear in the logger, but not in the switcher.

This has been the case for as long as I can remember, and something similar only happens on Slack. I've done all sequences of reloading with/without the logger open.

This was reported in #237 but it doesn't look like a resolution was reached.

Adding a rule like the following fixes the site as expected. The issue is that the fetch doesn't appear anywhere in the switcher, whether blocked or not.

slack.com slack-imgs.com fetch allow

A specific URL where the issue occurs

https://app.slack.com/client/T029RQSE6/CHQL7VCKU

Steps to Reproduce

Log in to Slack with a strict ruleset. Access a channel with images.

Ruleset

https-strict: * true
https-strict: behind-the-scene false
matrix-off: 127.0.0.1 true
matrix-off: about-scheme true
matrix-off: behind-the-scene true
matrix-off: chrome-extension-scheme true
matrix-off: chrome-scheme true
matrix-off: localhost true
matrix-off: wyciwyg-scheme true
noscript-spoof: * true
referrer-spoof: * true
referrer-spoof: behind-the-scene false
* * * block
* * cookie block
* * css allow
* * frame block
* * image allow
* * other block
* * script block
* 1st-party * allow
* 1st-party frame allow
slack.com * script inherit
slack.com 1st-party cookie allow
slack.com slack-edge.com * allow
slack.com slack-msgs.com fetch allow

Supporting evidence

Your environment

• uMatrix version: 1.4.1b0
• Browser Name and version: Chrome 83
• Operating System and version: macOS 10.15.4

[uBlock-user]

behind-the-scene/tabless requests will never appear in the popup panel, only in the logger.

[uBlock-user]

[FiloSottile]

Any docs on what makes a request "behind-the-scene"? Searching the wiki doesn't yield anything.

[uBlock-user]

docs haven't been added as it's not actively maintained, but gorhill's explanation - https://github.com/uBlockOrigin/uMatrix-issues/issues/62#issuecomment-423931783

[gorhill]

This is a duplicate of https://github.com/uBlockOrigin/uMatrix-issues/issues/92.

[uBlock-user]

92

you mean #62 ?

[gorhill]

92 is correct, more specifically, this comment.