From db8a113bb471559ebac85cfa90a7972e85bbc561 Mon Sep 17 00:00:00 2001
From: peter279k <peter279k@gmail.com>
Date: Tue, 19 Feb 2019 14:15:00 +0800
Subject: [PATCH] Issue #17

---
 src/Variables/VariableProvider.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Variables/VariableProvider.php b/src/Variables/VariableProvider.php
index 750c061..aa29279 100644
--- a/src/Variables/VariableProvider.php
+++ b/src/Variables/VariableProvider.php
@@ -172,7 +172,7 @@ private function fetchVariable($variable_name, $type)
      */
     private function checkVariableExists($variable, $type)
     {
-        if (($type === 'env'         && !getenv($variable)) ||
+        if (($type === 'env'         && false === getenv($variable)) ||
             ($type === 'replacement' && !$this->rstore->arrayKeyExists($variable)) ||
             ($type === 'variable'    && !$this->vstore->arrayKeyExists($variable))
         ) {