From ab3bb20383d6dbf9baa811d06414ee474bb8f91e Mon Sep 17 00:00:00 2001
From: Father Chrysostomos <sprout@cpan.org>
Date: Wed, 1 Nov 2017 13:11:27 -0700
Subject: [PATCH] =?UTF-8?q?Carp:=20Don=E2=80=99t=20choke=20on=20ISA=20cons?=
 =?UTF-8?q?tant?=
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This broke some time between 1.29 (perl 5.18) and 1.3301 (perl 5.20):

$ perl5.20.1 -e 'package Foo { use constant ISA => 42; Bar::f() } package Bar { use Carp; sub f { carp "tun syn" } }'
Not a GLOB reference at /usr/local/lib/perl5/5.20.1/Carp.pm line 560.

and still persisted in bleadperl (Carp 1.43) until this commit.

The code that goes poking through the symbol table needs to take into
account that not all stash elements are globs.

Petr Písař: Ported to 5.24.3.

Signed-off-by: Petr Písař <ppisar@redhat.com>
---
 dist/Carp/lib/Carp.pm |  3 ++-
 dist/Carp/t/Carp.t    | 13 ++++++++++++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/dist/Carp/lib/Carp.pm b/dist/Carp/lib/Carp.pm
index 92f8866..f94b9d4 100644
--- a/dist/Carp/lib/Carp.pm
+++ b/dist/Carp/lib/Carp.pm
@@ -594,7 +594,8 @@ sub trusts_directly {
     for my $var (qw/ CARP_NOT ISA /) {
         # Don't try using the variable until we know it exists,
         # to avoid polluting the caller's namespace.
-        if ( $stash->{$var} && *{$stash->{$var}}{ARRAY} && @{$stash->{$var}} ) {
+        if ( $stash->{$var} && ref \$stash->{$var} eq 'GLOB'
+          && *{$stash->{$var}}{ARRAY} && @{$stash->{$var}} ) {
            return @{$stash->{$var}}
         }
     }
diff --git a/dist/Carp/t/Carp.t b/dist/Carp/t/Carp.t
index 9ecdf88..f981005 100644
--- a/dist/Carp/t/Carp.t
+++ b/dist/Carp/t/Carp.t
@@ -3,7 +3,7 @@ no warnings "once";
 use Config;
 
 use IPC::Open3 1.0103 qw(open3);
-use Test::More tests => 66;
+use Test::More tests => 67;
 
 sub runperl {
     my(%args) = @_;
@@ -478,6 +478,17 @@ SKIP:
     );
 }
 
+{
+    package Mpar;
+    sub f { Carp::croak "tun syn" }
+
+    package Phou;
+    $Phou::{ISA} = \42;
+    eval { Mpar::f };
+}
+like $@, qr/tun syn/, 'Carp can handle non-glob ISA stash elems';
+
+
 # New tests go here
 
 # line 1 "XA"
-- 
2.13.6