From 8e57a61aed437f75b8af7df60c18e26b877a4e7d Mon Sep 17 00:00:00 2001
From: Richard Harrison <rjh@zaretto.com>
Date: Sun, 20 Jan 2019 18:08:34 +0100
Subject: [PATCH] Fix null ref during load.

This happened a few times
---
 simgear/scene/sky/cloud.cxx | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/simgear/scene/sky/cloud.cxx b/simgear/scene/sky/cloud.cxx
index 3c03c514..89a964b7 100644
--- a/simgear/scene/sky/cloud.cxx
+++ b/simgear/scene/sky/cloud.cxx
@@ -485,9 +485,11 @@ SGCloudLayer::rebuild()
 // repaint the cloud layer colors
 bool SGCloudLayer::repaint( const SGVec3f& fog_color ) {
     osg::Vec4f combineColor(toOsg(fog_color), cloud_alpha);
-    osg::TexEnvCombine* combiner
-        = dynamic_cast<osg::TexEnvCombine*>(layer_root->getStateSet()
-                                            ->getTextureAttribute(1, osg::StateAttribute::TEXENV));
+    osg::StateAttribute* textureAtt = layer_root->getStateSet()->getTextureAttribute(1, osg::StateAttribute::TEXENV);
+    osg::TexEnvCombine* combiner = dynamic_cast<osg::TexEnvCombine*>(textureAtt);
+
+    if (combiner == nullptr)
+        return false;
     combiner->setConstantColor(combineColor);
 
     // Set the fog color for the 3D clouds too.