This solves the issue where Insert/Cancel did not display in Hathor and Beez.
We have other issues concerning the thumbnails display in Beez and the floating of EDit/Cancel in Hathor, but they are unrelated.

I have tested this item successfully on 9174708

@waader @bertmert
We need a second test on this one.

I have tested this item successfully on 9174708

Regarding B/C, we actually excluded the rendered markup from being covered.
See https://developer.joomla.org/cms/development-strategy.html#backward_compatibility point 6.1.7

6.1.7 Rendered markup

For the time being, rendered markup is not subject to our backwards compatibility promise. We will try not to change markup in such a way that a site might render differently, but we can't promise not to break anything at the present time.

Imho, it should be fine to use BS tabs. Any decent template should support it.

We don’t have to break something here and also the tabs WILL be available for the bootstrap layout.

Yeah, but the bootstrap layout is only used by Protostar.
So while it is nice for Protostar, for most installation it will do nothing as that layout would have to be copied manually over to the active template.
So yes, we can advertise that we no longer have MooTools loaded, but it's only true for Protostar

Don't want to argue much, just saying that B/C isn't really that important here and using a feature which was present since 3.0 isn't something we have to avoid like the plaque.

@Bakual
Do you propose then that we make overrides for Hathor and Beez?

No, not an override but get the tabs working in those templates. Only use an override for deisgn reasons, not because the tabs aren't working.

3rd party extensions use those tabs, and templates are supposed to support them.
Keep in mind it's a feature we ship with core and thus is available for extension developers since 3.0.0.

@Bakual

Keep in mind it's a feature we ship with core and thus is available for extension developers since 3.0.0.

I do keep this in mind. The issue here is that the project ships in core 2 templates with an obvious display mess.

Hmm, we do need indeed to add a lot of css...

For the moment I can get this in Hathor, mainly by copy/paste of the css available in Isis:

before change

after change

Although this works, I must say I certainly did not do a clean job...
We need a good CSS specialist

The issue here is that the project ships in core 2 templates with an obvious display mess.

I fully agree with that. However I don't think we need to cater for those when we want to improve the core output. I think we all agree those two templates are well over their time.

If we do the changes global in com_media then every template will be affected. From my point of view there is gonna be a flood of bad comments in the forums for this change. Is this necessary at this point? I mean there are devs that are already pissed off, let’s keep some sanity for implementers and users…

Then don't do it at all.
Having templates overrides for Protostar is bad because we don't test our core output anymore.

However from my understanding any decent template will have no issues at all. As long as Bootstrap tabs are supported (which they really should!), then they will work.
If they don't support it, they already have some 3rd party extensions failing.

What is decided here?
If PLT decides this is not the correct way, please close the PR and we will try to solve the issue for Hathor and Beez in another PR.

Merged