Split out core of sv_magic() into sv_magicext().

sv_magic provides the extra restictions (no READONLY, only
one of each type, canned set of vtables), and sv_magicext()
does the actual data twiddling.
Also enhances semantics of ->mg_ptr setting via name/namlen
to allow either an uncopied ptr (namlen == 0), or a Newz()ed
scratch area (namlen > 0 && name == NULL).
sv_magicext also returns the MAGIC * it added.
sv_magicext is intended mainly for PERL_MAGIC_ext (~) magic.

To come sv_unmagicext() - which will remove just one magic
of particular type, and additionaly match against ->mg_ptr,
or the MAGIC * (need to experiment as to which is more natural).

p4raw-id: //depot/perlio@14335

1 files changed, 1 insertions, 0 deletions

diff --git a/proto.h b/proto.h
index fc67d8eafa..b93bb2c525 100644
--- a/proto.h
+++ b/proto.h
@@ -758,6 +758,7 @@ PERL_CALLCONV int	Perl_sv_isobject(pTHX_ SV* sv);
 PERL_CALLCONV STRLEN	Perl_sv_len(pTHX_ SV* sv);
 PERL_CALLCONV STRLEN	Perl_sv_len_utf8(pTHX_ SV* sv);
 PERL_CALLCONV void	Perl_sv_magic(pTHX_ SV* sv, SV* obj, int how, const char* name, I32 namlen);
+PERL_CALLCONV MAGIC *	Perl_sv_magicext(pTHX_ SV* sv, SV* obj, int how, MGVTBL *vtbl, const char* name, I32 namlen	);
 PERL_CALLCONV SV*	Perl_sv_mortalcopy(pTHX_ SV* oldsv);
 PERL_CALLCONV SV*	Perl_sv_newmortal(pTHX);
 PERL_CALLCONV SV*	Perl_sv_newref(pTHX_ SV* sv);