Strange admin behaviour on Django 3.1b1 with Firefox

[Claude Paroz]

On Firefox (68 ESR), when trying to display any model changelist page, I find myself with the nav-sidebar taking the whole page widths (changelist itself is completely hidden).

[Mariusz Felisiak]

Unfortunately I cannot reproduce this issue on Firefox 77 or Chrome, can you provide more details or a sample project?

[Claude Paroz]

It is not specific to a project, I reproduce that behavior with different projects.
I suspect this is an issue with Firefox 68. Are we going to only support the latest versions of browsers for the admin? Firefox 68 ESR is still the default browser of Debian stable (buster).

I noticed this is related with flex properties on the navbar without the parent div having the display: flex. When I add the display: flex; style attribute to the parent div#main, it works. But I'm far from sure this is the right fix.

I'm reopening because even if it would be decided not to fix it, it should be documented at least.

[Carlton Gibson]

Two things going on here.

1. The parent element should have display: flex.
2. Browser support.

On 1. This looks to be the case.

​From base.css:

#container > .main {
    display: flex;
    flex: 1 0 auto;
}

Disabling that in the inspector causes the issue described.

So where and why exactly is it not being set? (Currently at needsinfo/worksforme.)

Then browser support: the intention of 8b30360322d4de6687e17ab267a856db4e3c78a6 for #31032 was precisely to support only the latest versions. With the current batch of evergreen browsers, you have to opt-out of being up to date. No doubt it won't last forever but, we seem to be in a belle époque from a maintenance perspective for browser support. I don't think we should willingly compromise that.

Nonetheless, Firefox ESR isn't that far behind. I think the discussion at least here should be moot.

If we can answer 1 that would help.

[Claude Paroz]

Pffff... you are right, it was most probably a caching issue with using an outdated base.css.

So sorry for wasted time :-(

[Carlton Gibson]

No worries! Always happy to look. :)