Zsolt: an excellent idea!  That shouldn't change the semantics of the function, and therefore is strictly a bug fix.  Which means we could potentially backport it, yes?

Obviously we only need to change it between string / list if we're going to have this problem, and that only happens when there are parameters.  So the change could be very narrow in scope.  Lovely!

R. David: Why did you remove Python 2.7 from the list?  We see the behavior there too.