Do not clear property selection when adding new properties, but instead correct positions of any open editor controls.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@63356 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/propgrid/propgrid.cpp

@@ -1564,6 +1564,9 @@ void wxPropertyGrid::PrepareAfterItemsAdded()
         Sort(wxPG_SORT_TOP_LEVEL_ONLY);
 
     RecalculateVirtualSize();
+
+    // Fix editor position
+    CorrectEditorWidgetPosY();
 }
 
 // -----------------------------------------------------------------------