There is an issue not only for non-breaking space, but also for other unicode spaces, see #7845. For example (excerpt from rails String#squish testcase) %{\u205f\u3000 A string surrounded by various unicode spaces, with tabs(\t\t), newlines(\n\n), unicode nextlines(\u0085\u0085) and many spaces( ). \u00a0\u2007}.
So I think that this ticket should be closed in favour of #7845.