From 2c3867044308b592c75592cc0e837fe26b29a740 Mon Sep 17 00:00:00 2001
From: Oliver Tonnhofer <olt@bogosoft.com>
Date: Thu, 6 Mar 2014 10:25:57 +0100
Subject: [PATCH] prevent double-free in mapnik::projection

A double-free can happen when init_proj4 is called outside of the
constructor (for projections with defer_proj_init=true) and when that
call fails. In this case proj_ctx_ is not set to NULL and then freed
again in the destructor. Set to null to avoid second pj_ctx_free call.

See #2170
---
 src/projection.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/projection.cpp b/src/projection.cpp
index e194f49da..08251a7f5 100644
--- a/src/projection.cpp
+++ b/src/projection.cpp
@@ -108,7 +108,10 @@ void projection::init_proj4() const
         proj_ = pj_init_plus_ctx(proj_ctx_, params_.c_str());
         if (!proj_)
         {
-            if (proj_ctx_) pj_ctx_free(proj_ctx_);
+            if (proj_ctx_) {
+                pj_ctx_free(proj_ctx_);
+                proj_ctx_ = 0;
+            }
             throw proj_init_error(params_);
         }
 #else