From 971a4e3d553f203c80c8d20f0e7822d682b7e9a8 Mon Sep 17 00:00:00 2001
From: Mischa POSLAWSKY <perl@shiar.org>
Date: Wed, 20 Nov 2013 12:13:58 +0100
Subject: [PATCH] avoid untie replacement for perl v5.18

Replacing a tied hash causes random behaviour and crashes with newer
versions of Perl (probably due to COW changes), so keep the slower tie.
---
 META.yml             |  2 +-
 lib/PLP/Tie/Delay.pm | 26 +++++++++++++-------------
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/META.yml b/META.yml
index 23a60fd..0f653bf 100644
--- a/META.yml
+++ b/META.yml
@@ -50,7 +50,7 @@ provides:
         version: 1.00
     PLP::Tie::Delay:
         file: lib/PLP/Tie/Delay.pm
-        version: 1.00
+        version: 1.01
     PLP::Tie::Headers:
         file: lib/PLP/Tie/Headers.pm
         version: 1.01
diff --git a/lib/PLP/Tie/Delay.pm b/lib/PLP/Tie/Delay.pm
index 0a2a0d5..9b9b52f 100644
--- a/lib/PLP/Tie/Delay.pm
+++ b/lib/PLP/Tie/Delay.pm
@@ -4,7 +4,7 @@ use strict;
 no strict 'refs';
 use warnings;
 
-our $VERSION = '1.00';
+our $VERSION = '1.01';
 
 =head1 PLP::Tie::Delay
 
@@ -19,15 +19,16 @@ This module is part of the PLP internals and probably not of any use to others.
 
 sub _replace {
 	my ($self) = @_;
-	untie %{ $self->[0] };
 
-	# I'd like to use *{ $self->[0] } = $self->[1]->(); here,
-	# but that causes all sorts of problems. The hash is accessible from
-	# within this sub, but not where its creation was triggered.
-	# Immediately after the triggering statement, the hash becomes available
-	# to all: even the scope where the previous access attempt failed.
-	
-	%{ $self->[0] } = %{ $self->[1]->() }
+	if ($] >= 5.018) {
+		my $code = delete $self->[1] or return;
+		$self->[0] = $code->();
+		return 1;
+	}
+
+	untie %{ $self->[0] };
+	%{ $self->[0] } = %{ $self->[1]->() };  # *{ $self->[0] } = $self->[1]->();
+	return;
 }
 
 sub TIEHASH {
@@ -67,13 +68,12 @@ sub EXISTS {
 
 sub FIRSTKEY {
 	my ($self) = @_;
-	$self->_replace;
-	return 'PLPdummy';
+	$self->_replace and return 'PLPdummy';
+	return each %{$self->[0]};
 }
 
 sub NEXTKEY {
-	# Let's hope this never happens. (It's shouldn't.)
-	return undef;
+	return each %{$_[0]->[0]};
 }
 
 sub UNTIE   { }
-- 
2.30.0