In message "[ruby-talk:01261] Re: A vote for old behavior"
    on 00/02/07, Dave Thomas <Dave / thomases.com> writes:
|> 
|> After discussing seriously at ruby-dev mail list, I changed my mind
|> (again) to restore old behavior.  Sorry for confusion I may cause.
|
|So, just to confirm - sub! and gsub! will return nil if there's no
|change.

Yes.