From 619fb173df99ce4466cbde0e6e07567464f3a478 Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Sun, 18 Jun 2017 16:20:12 +0200
Subject: [PATCH] fix crash when argument list of openTransaction() is empty

---
 src/App/DocumentPyImp.cpp | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/App/DocumentPyImp.cpp b/src/App/DocumentPyImp.cpp
index ce7bda4983..249fe4e0a9 100644
--- a/src/App/DocumentPyImp.cpp
+++ b/src/App/DocumentPyImp.cpp
@@ -326,18 +326,21 @@ PyObject*  DocumentPy::moveObject(PyObject *args)
 
 PyObject*  DocumentPy::openTransaction(PyObject *args)
 {
-    PyObject *value;
+    PyObject *value = 0;
     if (!PyArg_ParseTuple(args, "|O",&value))
         return NULL;    // NULL triggers exception
     std::string cmd;
 
 
+    if (!value) {
+        cmd = "<empty>";
+    }
 #if PY_MAJOR_VERSION >= 3
-    if (PyUnicode_Check(value)) {
+    else if (PyUnicode_Check(value)) {
         cmd = PyUnicode_AsUTF8(value);
     }
 #else
-    if (PyUnicode_Check(value)) {
+    else if (PyUnicode_Check(value)) {
         PyObject* unicode = PyUnicode_AsLatin1String(value);
         cmd = PyString_AsString(unicode);
         Py_DECREF(unicode);