From 5e5699c4d8e1bda79a957d35c9636b150cdaf3c5 Mon Sep 17 00:00:00 2001
From: Gary Preston <gary@mups.co.uk>
Date: Wed, 5 Apr 2017 17:49:58 +0100
Subject: [PATCH] Return reference to non temporary string.

---
 tests/fake_sgSky.cxx | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tests/fake_sgSky.cxx b/tests/fake_sgSky.cxx
index 492403c7f..2940d5aa9 100644
--- a/tests/fake_sgSky.cxx
+++ b/tests/fake_sgSky.cxx
@@ -1,5 +1,7 @@
 #include "fake_sgSky.hxx"
 
+static const std::string sEmptyString;
+
 void SGSky::add_cloud_layer(SGCloudLayer *layer)
 {
     _cloudLayers.push_back(layer);
@@ -22,12 +24,12 @@ void SGSky::set_clouds_enabled(bool enabled)
 
 const std::string &SGCloudLayer::getCoverageString() const
 {
-    return std::string();
+    return sEmptyString;
 }
 
 const std::string &SGCloudLayer::getCoverageString(SGCloudLayer::Coverage coverage)
 {
-    return std::string();
+    return sEmptyString;
 }
 
 void SGCloudLayer::setCoverageString(const std::string &coverage)