From ac6ceea7641d6c19c71079e22b03b4c1519c0c94 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Tue, 1 Apr 2014 17:04:38 +0200
Subject: [PATCH] Fix potential segfault

The newEnv variable was accessed (via the dynamicEnv) pointer after it
had gone out of scope.

Fixes #234.
---
 src/libexpr/nixexpr.cc | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/libexpr/nixexpr.cc b/src/libexpr/nixexpr.cc
index 9f0bc2630..bca2b7913 100644
--- a/src/libexpr/nixexpr.cc
+++ b/src/libexpr/nixexpr.cc
@@ -242,9 +242,10 @@ void ExprOpHasAttr::bindVars(const StaticEnv & env)
 
 void ExprAttrs::bindVars(const StaticEnv & env)
 {
-    const StaticEnv *dynamicEnv = &env;
+    const StaticEnv * dynamicEnv = &env;
+    StaticEnv newEnv(false, &env);
+
     if (recursive) {
-        StaticEnv newEnv(false, &env);
         dynamicEnv = &newEnv;
 
         unsigned int displ = 0;