py3: path: some fixes to make path py3-compileable

src/Mod/Path/App/AppPath.cpp

@@ -58,7 +58,7 @@ PyMOD_INIT_FUNC(Path)
     }
     catch(const Base::Exception& e) {
         PyErr_SetString(PyExc_ImportError, e.what());
-        return;
+        PyMOD_Return(NULL);
     }
 
     PyObject* pathModule = Path::initModule();

src/Mod/Path/App/AppPathPy.cpp

@@ -416,8 +416,12 @@ private:
             PyTuple_SetItem(ret,0,list);
             PyTuple_SetItem(ret,1,new Base::VectorPy(
                         Base::Vector3d(pend.X(),pend.Y(),pend.Z())));
-            if(need_arc_plane) 
+            if(need_arc_plane)
+#if PY_MAJOR_VERSION < 3
                 PyTuple_SetItem(ret,2,PyInt_FromLong(arc_plane));
+#else
+                PyTuple_SetItem(ret,2,PyLong_FromLong(arc_plane));
+#endif
             return Py::asObject(ret);
         } PATH_CATCH
     }

src/Mod/Path/App/AreaPyImp.cpp

@@ -92,9 +92,13 @@ static PyObject * areaGetParamsDesc(PyObject *, PyObject *args, PyObject *kwd) {
     if (!PyArg_ParseTupleAndKeywords(args, kwd, "|O",kwlist,&pcObj))
         return 0;
 
+#if PY_MAJOR_VERSION < 3
     if(PyObject_IsTrue(pcObj)) 
         return PyString_FromString(PARAM_PY_DOC(NAME,AREA_PARAMS_STATIC_CONF));
-
+#else
+    if(PyObject_IsTrue(pcObj)) 
+        return PyUnicode_FromString(PARAM_PY_DOC(NAME,AREA_PARAMS_STATIC_CONF));
+#endif
     PyObject *dict = PyDict_New();
     PARAM_PY_DICT_SET_DOC(dict,NAME,AREA_PARAMS_STATIC_CONF)
     return dict;

src/Mod/Path/App/ParamsHelper.h

@@ -858,9 +858,14 @@
 #define PARAM_REF(_src,_seq) \
     BOOST_PP_SEQ_FOR_EACH_I(PARAM_REF_,_src,_seq)
 
+#if PY_MAJOR_VERSION < 3
+    #define PARAM_CAST_PYOBJ_short(_v)   PyInt_FromLong(_v)
+    #define PARAM_CAST_PYOBJ_long(_v)    PyInt_FromLong(_v)
+#else
+    #define PARAM_CAST_PYOBJ_short(_v)   PyLong_FromLong(_v)
+    #define PARAM_CAST_PYOBJ_long(_v)    PyLong_FromLong(_v)
+#endif
 
-#define PARAM_CAST_PYOBJ_short(_v)   PyInt_FromLong(_v)
-#define PARAM_CAST_PYOBJ_long(_v)    PyInt_FromLong(_v)
 #define PARAM_CAST_PYOBJ_double(_v)  PyFloat_FromDouble(_v)
 #define PARAM_CAST_PYOBJ_bool(_v)    ((_v)?Py_True:Py_False)
 #define PARAM_CAST_PYOBJ_enum        PARAM_CAST_PYOBJ_short
@@ -870,9 +875,13 @@
 /** Stringize field to a Python string 
  * \ingroup ParamPy ParamStringizer
  */
+#if PY_MAJOR_VERSION < 3
 #define PARAM_PY_STR(_field,_param)  \
     PyString_FromString(PARAM_FIELD_STR(_field,_param))
-
+#else
+#define PARAM_PY_STR(_field,_param)  \
+    PyUnicode_FromString(PARAM_FIELD_STR(_field,_param))
+#endif
 /** Helper for #PARAM_PY_DICT_SET_VALUE */
 #define PARAM_PY_DICT_SET_VALUE_(_1,_args,_param) \
     PyDict_SetItem(BOOST_PP_TUPLE_ELEM(0,_args), \
@@ -920,10 +929,17 @@
 #define PARAM_PY_DICT_DOC_enum2 PARAM_PY_DICT_DOC_enum
 
 /** Helper for #PARAM_PY_DICT_SET_DOC */
+#if PY_MAJOR_VERSION < 3
 #define PARAM_PY_DICT_SET_DOC_(_1,_args,_param) \
     PyDict_SetItem(BOOST_PP_TUPLE_ELEM(0,_args), \
             PARAM_PY_STR(BOOST_PP_TUPLE_ELEM(1,_args),_param),\
             PyString_FromString(PARAM_TYPED(PARAM_PY_DICT_DOC_,_param)(_param)));
+#else
+#define PARAM_PY_DICT_SET_DOC_(_1,_args,_param) \
+    PyDict_SetItem(BOOST_PP_TUPLE_ELEM(0,_args), \
+            PARAM_PY_STR(BOOST_PP_TUPLE_ELEM(1,_args),_param),\
+            PyUnicode_FromString(PARAM_TYPED(PARAM_PY_DICT_DOC_,_param)(_param)));
+#endif
 
 /** Populate a Python dict with the doc field of the parameter sequence
  *