App: correctly handle int as argument for ocumentPy::getObject

Add a unit test to confirm correct behaviour

src/App/DocumentPyImp.cpp

@@ -564,20 +564,33 @@ PyObject* DocumentPy::purgeTouched(PyObject* args)
     Py_Return;
 }
 
-PyObject*  DocumentPy::getObject(PyObject *args)
+PyObject* DocumentPy::getObject(PyObject *args)
 {
-    long id = -1;
-    char *sName = 0;
-    if (!PyArg_ParseTuple(args, "s",&sName))  {
-        if (!PyArg_ParseTuple(args, "l", &id))
-            return nullptr;
-    }
+    DocumentObject* obj = nullptr;
 
-    DocumentObject *pcFtr = sName?getDocumentPtr()->getObject(sName):getDocumentPtr()->getObjectByID(id);
-    if (pcFtr)
-        return pcFtr->getPyObject();
-    else
-        Py_Return;
+    do {
+        char* name = nullptr;
+        if (PyArg_ParseTuple(args, "s", &name))  {
+            obj = getDocumentPtr()->getObject(name);
+            break;
+        }
+
+        PyErr_Clear();
+        long id = -1;
+        if (PyArg_ParseTuple(args, "l", &id)) {
+            obj = getDocumentPtr()->getObjectByID(id);
+            break;
+        }
+
+        PyErr_SetString(PyExc_TypeError, "a string or integer is required");
+        return nullptr;
+    }
+    while (0);
+
+    if (obj)
+        return obj->getPyObject();
+
+    Py_Return;
 }
 
 PyObject*  DocumentPy::getObjectsByLabel(PyObject *args)

src/Mod/Test/Document.py

@@ -33,6 +33,17 @@ class DocumentBasicCases(unittest.TestCase):
   def setUp(self):
     self.Doc = FreeCAD.newDocument("CreateTest")
 
+  def testAccessByNameOrID(self):
+    obj = self.Doc.addObject("App::DocumentObject", "MyName")
+
+    with self.assertRaises(TypeError):
+      self.Doc.getObject([1])
+
+    self.assertEqual(self.Doc.getObject(obj.Name), obj)
+    self.assertEqual(self.Doc.getObject("Unknown"), None)
+    self.assertEqual(self.Doc.getObject(obj.ID), obj)
+    self.assertEqual(self.Doc.getObject(obj.ID+1), None)
+
   def testCreateDestroy(self):
     #FIXME: Causes somehow a ref count error but it's _not_ FreeCAD.getDocument()!!!
     #If we remove the whole method no error appears.