Don’t croak for local *DetachedStash::method

save_gp was trying to call mro_method_changed_in even if the stash had
been detached.

This is a regression from 5.12.

1 files changed, 8 insertions, 1 deletions

diff --git a/t/mro/basic.t b/t/mro/basic.t
index 10aa44cbc4..cc1386c5f4 100644
--- a/t/mro/basic.t
+++ b/t/mro/basic.t
@@ -3,7 +3,7 @@
 use strict;
 use warnings;
 
-BEGIN { require q(./test.pl); } plan(tests => 54);
+BEGIN { require q(./test.pl); } plan(tests => 55);
 
 require mro;
 
@@ -346,3 +346,10 @@ is(eval { MRO_N->testfunc() }, 123);
     @{*fednu::ISA} = "pyfg";
     ok +fednu->isa("pyfg"), 'autovivifying @ISA via *{@ISA}';
 }
+
+{
+    sub Detached::method;
+    my $h = delete $::{"Detached::"};
+    eval { local *Detached::method };
+    is $@, "", 'localising gv-with-cv belonging to detached package';
+}