From: Niko Tyni <ntyni@debian.org>
Subject: Fix a NULL pointer dereference when looking for a DESTROY method
Bug-Debian: http://bugs.debian.org/564074
Bug: http://rt.perl.org/rt3/Public/Bug/Display.html?id=71952
Origin: upstream, http://perl5.git.perl.org/perl.git/commit/1f15e670edb515b744e9021b4a42a7955da83093
 
The empty DESTROY method optimization introduced by upstream commit
fbb3ee5af3d would crash the interpreter if a DESTROY method was declared
but not actually defined.


---
 sv.c          |    3 ++-
 t/op/method.t |   11 ++++++++++-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/sv.c b/sv.c
index d2fcb0c..ec1ac82 100644
--- a/sv.c
+++ b/sv.c
@@ -5419,7 +5419,8 @@ Perl_sv_clear(pTHX_ register SV *sv)
 		if (destructor
 			/* Don't bother calling an empty destructor */
 			&& (CvISXSUB(destructor)
-			|| CvSTART(destructor)->op_next->op_type != OP_LEAVESUB))
+			|| (CvSTART(destructor)
+			    && (CvSTART(destructor)->op_next->op_type != OP_LEAVESUB))))
 		{
 		    SV* const tmpref = newRV(sv);
 	            SvREADONLY_on(tmpref);   /* DESTROY() could be naughty */
diff --git a/t/op/method.t b/t/op/method.t
index 46c4642..8e91c48 100755
--- a/t/op/method.t
+++ b/t/op/method.t
@@ -10,7 +10,7 @@ BEGIN {
     require "test.pl";
 }
 
-print "1..78\n";
+print "1..79\n";
 
 @A::ISA = 'B';
 @B::ISA = 'C';
@@ -293,3 +293,12 @@ EOT
 	"check if UNIVERSAL::AUTOLOAD works",
     );
 }
+{
+    fresh_perl_is(<<'EOT',
+sub M::DESTROY; bless {}, "M" ; print "survived\n";
+EOT
+    "survived",
+    {},
+	"no crash with a declared but missing DESTROY method"
+    );
+}
-- 
tg: (daf8b46..) fixes/crash-on-undefined-destroy (depends on: upstream)