Handle null TopoDS objects in the relevant typemap

Trying to solve tpaviot#600

Author: adam-urbanczyk

src/SWIG_files/common/FunctionTransformers.i

@@ -128,44 +128,46 @@ FairCurve_Analysis & function transformation
 }
 
 %typemap(out) TopoDS_Shape {
-    TopAbs_ShapeEnum shape_type = $1.ShapeType();
     PyObject *resultobj = 0;
- switch (shape_type)
-    {
- case TopAbs_COMPOUND:
-        resultobj = SWIG_NewPointerObj((new TopoDS_Compound(static_cast< const TopoDS_Compound& >($1))),
-                                        SWIGTYPE_p_TopoDS_Compound, SWIG_POINTER_OWN |  0 );
- break;
- case TopAbs_COMPSOLID:
-        resultobj = SWIG_NewPointerObj((new TopoDS_CompSolid(static_cast< const TopoDS_CompSolid& >($1))),
-                                        SWIGTYPE_p_TopoDS_CompSolid, SWIG_POINTER_OWN |  0 );
- break;
- case TopAbs_SOLID:
-        resultobj = SWIG_NewPointerObj((new TopoDS_Solid(static_cast< const TopoDS_Solid& >($1))),
-                                        SWIGTYPE_p_TopoDS_Solid, SWIG_POINTER_OWN |  0 );
- break;
- case TopAbs_SHELL:
-        resultobj = SWIG_NewPointerObj((new TopoDS_Shell(static_cast< const TopoDS_Shell& >($1))),
-                                        SWIGTYPE_p_TopoDS_Shell, SWIG_POINTER_OWN |  0 );
- break;
- case TopAbs_FACE:
-        resultobj = SWIG_NewPointerObj((new TopoDS_Face(static_cast< const TopoDS_Face& >($1))),
-                                        SWIGTYPE_p_TopoDS_Face, SWIG_POINTER_OWN |  0 );
- break;
- case TopAbs_WIRE:
-        resultobj = SWIG_NewPointerObj((new TopoDS_Wire(static_cast< const TopoDS_Wire& >($1))),
-                                        SWIGTYPE_p_TopoDS_Wire, SWIG_POINTER_OWN |  0 );
- break;
- case TopAbs_EDGE:
-        resultobj = SWIG_NewPointerObj((new TopoDS_Edge(static_cast< const TopoDS_Edge& >($1))),
-                                        SWIGTYPE_p_TopoDS_Edge, SWIG_POINTER_OWN |  0 );
- break;
- case TopAbs_VERTEX:
-        resultobj = SWIG_NewPointerObj((new TopoDS_Vertex(static_cast< const TopoDS_Vertex& >($1))),
-                                        SWIGTYPE_p_TopoDS_Vertex, SWIG_POINTER_OWN |  0 );
- break;
- default:
- break;
+ if(!$1.IsNull()){
+        TopAbs_ShapeEnum shape_type = $1.ShapeType();
+ switch (shape_type)
+        {
+ case TopAbs_COMPOUND:
+            resultobj = SWIG_NewPointerObj((new TopoDS_Compound(static_cast< const TopoDS_Compound& >($1))),
+                                            SWIGTYPE_p_TopoDS_Compound, SWIG_POINTER_OWN |  0 );
+ break;
+ case TopAbs_COMPSOLID:
+            resultobj = SWIG_NewPointerObj((new TopoDS_CompSolid(static_cast< const TopoDS_CompSolid& >($1))),
+                                            SWIGTYPE_p_TopoDS_CompSolid, SWIG_POINTER_OWN |  0 );
+ break;
+ case TopAbs_SOLID:
+            resultobj = SWIG_NewPointerObj((new TopoDS_Solid(static_cast< const TopoDS_Solid& >($1))),
+                                            SWIGTYPE_p_TopoDS_Solid, SWIG_POINTER_OWN |  0 );
+ break;
+ case TopAbs_SHELL:
+            resultobj = SWIG_NewPointerObj((new TopoDS_Shell(static_cast< const TopoDS_Shell& >($1))),
+                                            SWIGTYPE_p_TopoDS_Shell, SWIG_POINTER_OWN |  0 );
+ break;
+ case TopAbs_FACE:
+            resultobj = SWIG_NewPointerObj((new TopoDS_Face(static_cast< const TopoDS_Face& >($1))),
+                                            SWIGTYPE_p_TopoDS_Face, SWIG_POINTER_OWN |  0 );
+ break;
+ case TopAbs_WIRE:
+            resultobj = SWIG_NewPointerObj((new TopoDS_Wire(static_cast< const TopoDS_Wire& >($1))),
+                                            SWIGTYPE_p_TopoDS_Wire, SWIG_POINTER_OWN |  0 );
+ break;
+ case TopAbs_EDGE:
+            resultobj = SWIG_NewPointerObj((new TopoDS_Edge(static_cast< const TopoDS_Edge& >($1))),
+                                            SWIGTYPE_p_TopoDS_Edge, SWIG_POINTER_OWN |  0 );
+ break;
+ case TopAbs_VERTEX:
+            resultobj = SWIG_NewPointerObj((new TopoDS_Vertex(static_cast< const TopoDS_Vertex& >($1))),
+                                            SWIGTYPE_p_TopoDS_Vertex, SWIG_POINTER_OWN |  0 );
+ break;
+ default:
+ break;
+        }
     }
  return resultobj;
 }