24 feb. 2019 kl. 20.06 skrev Eli Zaretskii <eliz@gnu.org>:
> 
> Your preferred solution is fine with me, FWIW.

Thank you; patch attached.

>> (Speaking of regexp-opt, it has another bug that does not affect rx: it returns the empty string if given an empty list of strings. The correct return value is a regexp that never matches anything. Fix it, document it, or turn it into an error?)
> 
> Fix it, I think.

I'll prepare another patch. Is there a preferred or particularly clever never-matching regexp? If not, would \(?:$\)A do?