Fix #4445: Removing worldspawn from the map prevents new brushes from…

… being drag-created

Was a regression introduced by the changes in the Map class

radiant/map/Map.cpp

@@ -151,6 +151,15 @@ bool Map::isUnnamed() const {
     return _mapName == _(MAP_UNNAMED_STRING);
 }
 
+void Map::onSceneNodeErase(const scene::INodePtr& node)
+{
+	// Detect when worldspawn is removed from the map
+	if (node == _worldSpawnNode)
+	{
+		_worldSpawnNode.reset();
+	}
+}
+
 void Map::setWorldspawn(const scene::INodePtr& node)
 {
     _worldSpawnNode = node;
@@ -966,6 +975,7 @@ const StringSet& Map::getDependencies() const
 	{
         _dependencies.insert(MODULE_RADIANT);
 		_dependencies.insert(MODULE_GAMEMANAGER);
+		_dependencies.insert(MODULE_SCENEGRAPH);
     }
 
     return _dependencies;
@@ -984,6 +994,8 @@ void Map::initialiseModule(const ApplicationContext& ctx)
         sigc::mem_fun(*_startupMapLoader, &StartupMapLoader::onRadiantShutdown)
     );
 
+	GlobalSceneGraph().addSceneObserver(this);
+
     // Add the Map-related commands to the EventManager
     registerCommands();
 
@@ -993,6 +1005,11 @@ void Map::initialiseModule(const ApplicationContext& ctx)
 	MapFileManager::registerFileTypes();
 }
 
+void Map::shutdownModule()
+{
+	GlobalSceneGraph().removeSceneObserver(this);
+}
+
 // Creates the static module instance
 module::StaticModule<Map> staticMapModule;
 

radiant/map/Map.h

@@ -5,6 +5,7 @@
 #include "imapformat.h"
 #include "inamespace.h"
 #include "imapresource.h"
+#include "iscenegraph.h"
 #include "icommandsystem.h"
 #include "imodule.h"
 #include "math/Vector3.h"
@@ -19,7 +20,8 @@ class TextInputStream;
 namespace map {
 
 class Map :
-	public IMap
+	public IMap,
+	public scene::Graph::Observer
 {
 	// The map name
 	std::string _mapName;
@@ -60,6 +62,10 @@ class Map :
 	virtual const std::string& getName() const override;
 	virtual const StringSet& getDependencies() const override;
 	virtual void initialiseModule(const ApplicationContext& ctx) override;
+	virtual void shutdownModule() override;
+
+	// Gets called when a node is removed from the scenegraph
+	virtual void onSceneNodeErase(const scene::INodePtr& node) override;
 
 	/** greebo: Returns true if the map has not been named yet.
 	 */