{
const U32 refcnt = SvREFCNT(sv);
SV_CHECK_THINKFIRST_COW_DROP(sv);
- if (SvREFCNT(nsv) != 1 && ckWARN_d(WARN_INTERNAL))
- Perl_warner(aTHX_ packWARN(WARN_INTERNAL), "Reference miscount in sv_replace()");
+ if (SvREFCNT(nsv) != 1) {
+ Perl_croak(aTHX_ "panic: reference miscount on nsv in sv_replace() (%"
+ UVuf " != 1)", (UV) SvREFCNT(nsv));
+ }
if (SvMAGICAL(sv)) {
if (SvMAGICAL(nsv))
mg_free(nsv);