From 9d6e27c85c1eb37b5eb2c501c9039316465cbffc Mon Sep 17 00:00:00 2001
From: Stuart Buchanan <stuart_d_buchanan@yahoo.co.uk>
Date: Tue, 19 Jun 2012 22:04:17 +0100
Subject: [PATCH] Do not attempt to reposition non-existant clouds.

Defensive workaround to Issue 678.
---
 simgear/scene/sky/cloudfield.cxx | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/simgear/scene/sky/cloudfield.cxx b/simgear/scene/sky/cloudfield.cxx
index 1d9ae9ea..18c7e8ef 100644
--- a/simgear/scene/sky/cloudfield.cxx
+++ b/simgear/scene/sky/cloudfield.cxx
@@ -130,6 +130,11 @@ bool SGCloudField::reposition( const SGVec3f& p, const SGVec3f& up, double lon,
             ++itr) {
               
              osg::ref_ptr<osg::PositionAttitudeTransform> pat = itr->second;
+            
+             if (pat == 0) {
+                continue;
+             }
+             
              osg::Vec3f currpos = field_transform->getPosition() + fta * pat->getPosition();
                                       
              // Determine the vector from the new position to the cloud in cloud-space.
@@ -367,7 +372,7 @@ void SGCloudField::addCloudToTree(osg::ref_ptr<osg::PositionAttitudeTransform> t
         
 bool SGCloudField::deleteCloud(int identifier) {
     osg::ref_ptr<osg::PositionAttitudeTransform> transform = cloud_hash[identifier];
-    if (transform == NULL) return false;
+    if (transform == 0) return false;
         
     removeCloudFromTree(transform);
     cloud_hash.erase(identifier);
-- 
2.39.5