From 4ab5bd5f1ac4d396ccef2207abef0c1e6fe14b66 Mon Sep 17 00:00:00 2001
From: Father Chrysostomos <sprout@cpan.org>
Date: Sat, 4 Jun 2011 19:14:33 -0700
Subject: [PATCH] Make Devel::Peek::fill_mstats work on COWs

---
 ext/Devel-Peek/Peek.xs  | 1 +
 ext/Devel-Peek/t/Peek.t | 8 ++++++++
 2 files changed, 9 insertions(+)

diff --git a/ext/Devel-Peek/Peek.xs b/ext/Devel-Peek/Peek.xs
index 3dcba47..5e8deb9 100644
--- a/ext/Devel-Peek/Peek.xs
+++ b/ext/Devel-Peek/Peek.xs
@@ -161,6 +161,7 @@ fill_mstats(SV *sv, int level)
 {
     dTHX;
 
+    if (SvIsCOW(sv)) sv_force_normal(sv);
     if (SvREADONLY(sv))
 	croak("Cannot modify a readonly value");
     SvGROW(sv, sizeof(struct mstats_buffer)+1);
diff --git a/ext/Devel-Peek/t/Peek.t b/ext/Devel-Peek/t/Peek.t
index 5c6b315..8eedf53 100644
--- a/ext/Devel-Peek/t/Peek.t
+++ b/ext/Devel-Peek/t/Peek.t
@@ -770,4 +770,12 @@ do_test('ENAMEs on a stash with no NAME',
     ENAME = "RWOM", "KLANK"			# $] > 5.012
 ');
 
+SKIP: {
+    skip "Not built with usemymalloc", 1
+      unless $Config{usemymalloc} eq 'y';
+    my $x = __PACKAGE__;
+    ok eval { fill_mstats($x); 1 }, 'fill_mstats on COW scalar'
+     or diag $@;
+}
+
 done_testing();
-- 
2.7.4