+ else
+ mg->mg_ptr = (char *) name;
+ }
+ mg->mg_virtual = vtable;
+
+ mg_magical(sv);
+ if (SvGMAGICAL(sv))
+ SvFLAGS(sv) &= ~(SVf_IOK|SVf_NOK|SVf_POK);
+ return mg;
+}
+
+/*
+=for apidoc sv_magic
+
+Adds magic to an SV. First upgrades C<sv> to type C<SVt_PVMG> if necessary,
+then adds a new magic item of type C<how> to the head of the magic list.
+
+=cut
+*/
+
+void
+Perl_sv_magic(pTHX_ register SV *sv, SV *obj, int how, const char *name, I32 namlen)
+{
+ MAGIC* mg;
+ MGVTBL *vtable = 0;
+
+ if (SvREADONLY(sv)) {
+ if (PL_curcop != &PL_compiling
+ && how != PERL_MAGIC_regex_global
+ && how != PERL_MAGIC_bm
+ && how != PERL_MAGIC_fm
+ && how != PERL_MAGIC_sv
+ )
+ {
+ Perl_croak(aTHX_ PL_no_modify);
+ }
+ }
+ if (SvMAGICAL(sv) || (how == PERL_MAGIC_taint && SvTYPE(sv) >= SVt_PVMG)) {
+ if (SvMAGIC(sv) && (mg = mg_find(sv, how))) {
+ /* sv_magic() refuses to add a magic of the same 'how' as an
+ existing one
+ */
+ if (how == PERL_MAGIC_taint)
+ mg->mg_len |= 1;
+ return;
+ }