Feature request: list tags occurring in combination

[crater2150]

When using the VFS, listing the directory of a tag a contains only the tags that occur on files also tagged with a.

I tried to achieve the same with the command line tools, but my best attempt still had some problems. But perhaps it makes clearer what I'm trying to get:

tmsu files A B | xargs tmsu tags -1 -n never | sort -u

This doesn't work, if there are no files tagged with both A and B and lists all tags instead. Also it lists the requested tags itself.

As the logic to find tags occurring together seems to already be there for the VFS, could this also be added to the tmsu command? I'd suggest an option to tmsu tags, e.g. like the --where option of tmsu tag.