Added clears of input vectors in various get*() methods

src/osgViewer/CompositeViewer.cpp

@@ -348,6 +348,8 @@ void CompositeViewer::getCameras(Cameras& cameras, bool onlyActive)
  
 void CompositeViewer::getScenes(Scenes& scenes, bool onlyValid)
 {
+    scenes.clear();
+
     typedef std::set<osgViewer::Scene*> SceneSet;
     SceneSet sceneSet;
 
@@ -369,6 +371,8 @@ void CompositeViewer::getScenes(Scenes& scenes, bool onlyValid)
 
 void CompositeViewer::getViews(Views& views, bool onlyValid)
 {
+    views.clear();
+
     for(RefViews::iterator vitr = _views.begin();
         vitr != _views.end();
         ++vitr)
@@ -379,6 +383,8 @@ void CompositeViewer::getViews(Views& views, bool onlyValid)
 
 void CompositeViewer::getAllThreads(Threads& threads, bool onlyActive)
 {
+    threads.clear();
+
     OperationThreads operationThreads;
     getOperationThreads(operationThreads);
     

src/osgViewer/Viewer.cpp

@@ -939,16 +939,20 @@ void Viewer::updateTraversal()
 
 void Viewer::getScenes(Scenes& scenes, bool onlyValid)
 {
+    scenes.clear();
     scenes.push_back(_scene.get());
 }
 
 void Viewer::getViews(Views& views, bool onlyValid)
 {
+    views.clear();
     views.push_back(this);
 }
 
 void Viewer::getAllThreads(Threads& threads, bool onlyActive)
 {
+    threads.clear();
+
     OperationThreads operationThreads;
     getOperationThreads(operationThreads);