Steps to reproduce
Expected result
Template should be substed and its source code should be saved
Current result
<ref>{{subst:some template}}</ref> is saved instead
I think that it's a feature, not a bug, but I don't know why this choice. I've known this for a long time.
@Framawiki OK, we should find out why it is a feature and not a bug then if you are right. Who could know this? On cswiki we have got some citation templates, which are created for substituting into ref tags and obviously don't work the way their author intended (e.g. https://cs.wikipedia.org/wiki/Šablona:Citace_koránu)
Yes, this is intentional. Because of the (bad) way the references system is designed, it doesn't actually support real wikitext, just a subset of it (and for performance, a quite limited one). The proper fix for this would be moving references to be a proper system; of the ideas around doing that, WikiCite is the most likely to happen (and even that won't be soon).