1594417 - Flickering in about:addons when switching between panels

Status: VERIFIED FIXED

(Toolkit :: Add-ons Manager, defect, P1)

Description

[Itiel]

This doesn't reproduce reliably on every Firefox session, but once this happens in a session, it's 100% reproducible.
The flickering is around the More Options button, displaying its contents briefly before disappearing.

See attached screencast.

Comment 1

[Itiel]

Attachment: Screencast

Comment 2

[Mark Striemer [:mstriemer]]

I also noticed this at one point but couldn't reproduce after a restart as well. Figured it was a local build issue, thanks for the report!

Comment 3

[Itiel]

(In reply to Mark Striemer [:mstriemer] from comment #2)

I also noticed this at one point but couldn't reproduce after a restart as well. Figured it was a local build issue, thanks for the report!

Well, I'm on a non-local build...
Did you have the browser toolbox open at that time, by any chance?

Comment 4

[Mark Striemer [:mstriemer]]

Attachment: Bug 1594417 - Ensure panel-list is hidden when added to document r?Gijs

When the stylesheet needs to load for panel-list it is missing the rule to
hide the panel while it's closed. Move this style into the shadow DOM so
it's always present even if the other styles haven't loaded yet.

This was especially noticeable when the "Disable Cache" option was enabled
with the devtools open.

Comment 5

[Mark Striemer [:mstriemer]]

Ah, that appeared to be it! With the disable cache option checked it would load the stylesheet each time and render without the style to hide the panel.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/dff542b772e5
Ensure panel-list is hidden when added to document r=Gijs

Comment 7

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/dff542b772e5

Comment 8

[Miruna Curtean]

Verified fixed on Windows PRO 10 64-bit and on macOS Catalina 10.15 with FF Nightly 72.0a1 (20191111215252).
Switching between the about:addons panels while devtools is open and the Disabled Cache Network option is checked/ unchecked did not reveal any flickering issues.