From a46f0e41056b48a56c572fe8884d4b5104a8343e Mon Sep 17 00:00:00 2001
From: Niko Tyni <ntyni@debian.org>
Date: Sun, 29 Jun 2014 21:51:15 +0300
Subject: [PATCH] multi_linestring2perl: only extend the array if needed

When the size is 0, we end up extending the stack with
a negative value. As of Perl 5.19.4, more precisely
 http://perl5.git.perl.org/perl.git/commit/fc16c3924bd6aa054f21ad5445fecf9b7f39dc36
this ends up allocating memory for 4G-1 elements.

See Dave Mitchell's comments on perl5-porters:
 Message-ID: <20140522115758.GX15438@iabyn.com>
 http://marc.info/?l=perl5-porters&m=140075990913228&w=2
---
 src/mline2av.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/mline2av.h b/src/mline2av.h
index e4b3fc2..d7bacee 100644
--- a/src/mline2av.h
+++ b/src/mline2av.h
@@ -9,7 +9,8 @@ multi_linestring2perl(pTHX_ const multi_linestring& mls)
 {
   AV* av = newAV();
   const unsigned int size = mls.size();
-  av_extend(av, size-1);
+  if (size > 0)
+    av_extend(av, size-1);
 
   for (int i = 0; i < size; i++) {
     AV* lineav = newAV();
-- 
2.0.0