SL-18708 Shutdown crash at renderHeavenlyBodies

indra/newview/lldrawpoolwlsky.cpp

@@ -451,6 +451,8 @@ void LLDrawPoolWLSky::renderSkyClouds(const LLVector3& camPosLocal, F32 camHeigh
 
 void LLDrawPoolWLSky::renderHeavenlyBodies()
 {
+    if (!gSky.mVOSkyp) return;
+
 	LLGLSPipelineBlendSkyBox gls_skybox(true, false);
 
     LLVector3 const & origin = LLViewerCamera::getInstance()->getOrigin();

indra/newview/llworld.cpp

@@ -38,6 +38,7 @@
 #include "llglheaders.h"
 #include "llhttpnode.h"
 #include "llregionhandle.h"
+#include "llsky.h"
 #include "llsurface.h"
 #include "lltrans.h"
 #include "llviewercamera.h"
@@ -117,6 +118,7 @@ void LLWorld::resetClass()
 {
 	mHoleWaterObjects.clear();
 	gObjectList.destroy();
+    gSky.cleanup(); // references an object
 	for(region_list_t::iterator region_it = mRegionList.begin(); region_it != mRegionList.end(); )
 	{
 		LLViewerRegion* region_to_delete = *region_it++;