fix some warnings

OpenMesh/OMPropertyModelT_impl.hh

@@ -70,8 +70,8 @@ OMPropertyModel<MeshT>::OMPropertyModel(MeshT* mesh, int objectID, QObject *pare
     : OMPropertyModelSubclass(parent),
       mesh_(mesh),
       objectID_(objectID),
-      mCombineProperty1(0),
-      mCombineProperty2(0),
+      mCombineProperty1(nullptr),
+      mCombineProperty2(nullptr),
       pickModeActive(false)
 {
     gatherProperties();
@@ -263,7 +263,7 @@ bool OMPropertyModel<MeshT>::parseHeader(QString header, PropertyVisualizer*& pr
 
         TypeInfoWrapper typeInfo = getSupportedTypeInfoWrapper(friendlyName);
 
-        QString propName = QInputDialog::getText(0, "Property Name", "Please enter name.",QLineEdit::Normal,headerParts[4]);
+        QString propName = QInputDialog::getText(nullptr, "Property Name", "Please enter name.",QLineEdit::Normal,headerParts[4]);
         if (propName == "") return false;
 
         bool replace = false;