Fix for probably unintended behavior

I based some code I wrote on a function from this package, which I think does not work as intended, so I wrote a patch. A comment says it is going to ignore a no-posts tag, unless there are no posts, while I think it does not (haven't tried to run it).
While I at it, merging all no-posts tags to form the result seems like the most appropriate thing to do (instead of using the first one and ignoring the rest). As a bonus, it's simpler.