Crashfix regarding LLViewerObject using released regions. V3 cherrypick.

indra/newview/llviewerobject.cpp

@@ -904,6 +904,13 @@ U32 LLViewerObject::processUpdateMessage(LLMessageSystem *mesgsys,
 	LLMemType mt(LLMemType::MTYPE_OBJECT);
 	U32 retval = 0x0;
 	
+	// If region is removed from the list it is also deleted.
+	if (!LLWorld::instance().isRegionListed(mRegionp))
+	{
+		llwarns << "Updating object in an invalid region" << llendl;
+		return retval;
+	}
+
 	// Coordinates of objects on simulators are region-local.
 	U64 region_handle;
 	mesgsys->getU64Fast(_PREHASH_RegionData, _PREHASH_RegionHandle, region_handle);
@@ -3556,7 +3563,8 @@ LLNameValue *LLViewerObject::getNVPair(const std::string& name) const
 
 void LLViewerObject::updatePositionCaches() const
 {
-	if(mRegionp)
+	// If region is removed from the list it is also deleted.
+	if(mRegionp && LLWorld::instance().isRegionListed(mRegionp))
 	{
 		if (!isRoot())
 		{
@@ -3573,7 +3581,8 @@ void LLViewerObject::updatePositionCaches() const
 
 const LLVector3d LLViewerObject::getPositionGlobal() const
 {	
-	if(mRegionp)
+	// If region is removed from the list it is also deleted.
+	if(mRegionp && LLWorld::instance().isRegionListed(mRegionp))
 	{
 		LLVector3d position_global = mRegionp->getPosGlobalFromRegion(getPositionRegion());
 
@@ -3592,7 +3601,8 @@ const LLVector3d LLViewerObject::getPositionGlobal() const
 
 const LLVector3 &LLViewerObject::getPositionAgent() const
 {
-	if (mRegionp)
+	// If region is removed from the list it is also deleted.
+	if(mRegionp && LLWorld::instance().isRegionListed(mRegionp))
 	{
 		if (mDrawable.notNull() && (!mDrawable->isRoot() && getParent()))
 		{

indra/newview/llworld.cpp

@@ -1486,6 +1486,11 @@ void LLWorld::getAvatars(std::vector<LLUUID>* avatar_ids, std::vector<LLVector3d
 	}
 }
 
+bool LLWorld::isRegionListed(const LLViewerRegion* region) const
+{
+	region_list_t::const_iterator it = find(mRegionList.begin(), mRegionList.end(), region);
+	return it != mRegionList.end();
+}
 
 LLHTTPRegistration<LLEstablishAgentCommunication>
 	gHTTPRegistrationEstablishAgentCommunication(

indra/newview/llworld.h

@@ -163,6 +163,11 @@ public:
 		std::vector<LLVector3d>* positions = NULL, 
 		const LLVector3d& relative_to = LLVector3d(), F32 radius = FLT_MAX) const;
 
+	// Returns 'true' if the region is in mRegionList,
+	// 'false' if the region has been removed due to region change
+	// or if the circuit to this simulator had been lost.
+	bool isRegionListed(const LLViewerRegion* region) const;
+
 private:
 	region_list_t	mActiveRegionList;
 	region_list_t	mRegionList;