This has been proposed long ago, but I cannot find a duplicate bug ID right now. The usual workaround for this is to duplicate the bug for each version of your project. When it's done in one version, you can resolve one bug. When it's done in the other, you can resolve the other.

Yes, thats possible I guess. Usually both get fixed and resolved within a day.. usually. So far we say "whats fixed in 1.2.x is fixed in 1.3.x or is not relevant". I'm not yet entirely happy about duplicating bugs as it does give a higher than required bug count (ok, yes the are bugs duplicated as the software is different but 99% of the time the reason is the bug was inherited by the 1.3.x series from its 1.2.x beginnings).

The "Create Clone" botton makes this easy. It creates a linked set of issues that can be resolved in different releases. I generally make the parent one the earliest release that has the issue, and the child(ren) the follow up releases. When the children are resolved, the parent will stop giving a "children are still open" message.

I think this would need to be handled by cloning the issue(s)

atm, fixed in version is a single field against a bug. Given most bugs are likely to only affect one version, I dont think their would be any useful value in trying to change this behaviour