From 042abef72d40ab7ff39127e2afae6e34dfc66404 Mon Sep 17 00:00:00 2001
From: Nicolas R <atoomic@cpan.org>
Date: Fri, 14 Aug 2020 16:16:22 -0500
Subject: [PATCH] die_unwind(): global destruction
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Fix #18063

During global destruction make sure we preserve
the string by using mortalcopy.

This is an update on 8c86f0238ecb5f32c2e7fba36e3edfdb54069068
change which avoided sv_mortalcopy in favor of sv_2mortal.

Signed-off-by: Petr Písař <ppisar@redhat.com>
---
 pp_ctl.c          | 6 +++++-
 t/op/die_unwind.t | 4 ++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/pp_ctl.c b/pp_ctl.c
index b8cd869ee0..cc244d7ba7 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -1716,7 +1716,11 @@ Perl_die_unwind(pTHX_ SV *msv)
          * when unlocalising a tied var). So we do a dance with
          * mortalising and SAVEFREEing.
          */
-        sv_2mortal(SvREFCNT_inc_simple_NN(exceptsv));
+        if (PL_phase == PERL_PHASE_DESTRUCT) {
+            exceptsv = sv_mortalcopy(exceptsv);
+        } else {
+            exceptsv = sv_2mortal(SvREFCNT_inc_simple_NN(exceptsv));
+        }
 
 	/*
 	 * Historically, perl used to set ERRSV ($@) early in the die
diff --git a/t/op/die_unwind.t b/t/op/die_unwind.t
index eee1ce534b..4b83ee6fac 100644
--- a/t/op/die_unwind.t
+++ b/t/op/die_unwind.t
@@ -69,4 +69,8 @@ is($uerr, "t3\n");
 is($val, undef, "undefined return value from 'eval' block with 'die'");
 is($err, "t3\n");
 
+fresh_perl_like(<<'EOS', qr/Custom Message During Global Destruction/, { switches => ['-w'], stderr => 1 } );
+package Foo; sub DESTROY { die "Custom Message During Global Destruction" }; package main; our $wut = bless [], "Foo"
+EOS
+
 done_testing();
-- 
2.25.4