[C pkgs (vc)]: [Bug: 21.4.18] can't check in SCCS file with new vc

[Stephen J. Turnbull]

Ville Skyttä writes:

 > > > (replace-match "p." t t master 2) produces "p.".  Aha!
 > > >
 > > > It looks like the replace-match sexp needs help.
 > >
 > > Thanks for the analysis, Mike!  Actually, I don't think we can sanely use
 > > replace-match in this case at all.

Do my patches to 21.5 address this issue?  (Your patch is still
needed, at least until Vin approves and releases a patched version of
21.4, of course.)