From 7e5d55b35d0c95380f436d0ebd75bab73fce8622 Mon Sep 17 00:00:00 2001
From: Tony Cook <tony@develop-help.com>
Date: Mon, 17 Jun 2024 15:24:38 +1000
Subject: [PATCH] class.c: store the stash in the constructor CV stash slot

This code previously stored the stash for the class in the CV's
any_cv slot, and marked that to be released when the CV is released.

But it does not bump the reference count of the stash that I can
see.

When I tried releasing the constructor SV while working on #22169
I found perl would crash, incrementing the stash reference count
prevents that, but leaves us with a reference loop.

But it turns out that CVs already have a slot to store their stash in
and an API that correctly handles reference counting for that slot.

So use CvSTASH_set()/CvSTASH() to manage the stash for "$class::new"
methods.
---
 class.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/class.c b/class.c
index ed7368136899..07bad10498c0 100644
--- a/class.c
+++ b/class.c
@@ -131,7 +131,7 @@ XS(injected_constructor)
 {
     dXSARGS;
 
-    HV *stash = (HV *)XSANY.any_sv;
+    HV *stash = CvSTASH(cv);
     assert(HvSTASH_IS_CLASS(stash));
 
     struct xpvhv_aux *aux = HvAUX(stash);
@@ -371,8 +371,7 @@ Perl_class_setup_stash(pTHX_ HV *stash)
         SAVEFREESV(newname);
 
         CV *newcv = newXS_flags(SvPV_nolen(newname), injected_constructor, __FILE__, NULL, nameflags);
-        CvXSUBANY(newcv).any_sv = (SV *)stash;
-        CvREFCOUNTED_ANYSV_on(newcv);
+        CvSTASH_set(newcv, stash);
     }
 
     /* TODO: