diff -r 648685f8d5e9 Modules/_tkinter.c
--- a/Modules/_tkinter.c	Thu Sep 04 21:00:10 2014 +0200
+++ b/Modules/_tkinter.c	Thu Sep 04 21:38:26 2014 +0200
@@ -912,15 +912,20 @@ AsObj(PyObject *value)
                                                    "list is too long");
             return NULL;
         }
-        argv = (Tcl_Obj **) ckalloc(((size_t)size) * sizeof(Tcl_Obj *));
-        if(!argv) {
-          PyErr_NoMemory();
-          return NULL;
+        if (size != 0) {
+            argv = (Tcl_Obj **) ckalloc(((size_t)size) * sizeof(Tcl_Obj *));
+            if(!argv) {
+              PyErr_NoMemory();
+              return NULL;
+            }
+            for (i = 0; i < size; i++)
+              argv[i] = AsObj(PySequence_Fast_GET_ITEM(value,i));
+            result = Tcl_NewListObj(size, argv);
+            ckfree(FREECAST argv);
         }
-        for (i = 0; i < size; i++)
-          argv[i] = AsObj(PySequence_Fast_GET_ITEM(value,i));
-        result = Tcl_NewListObj(size, argv);
-        ckfree(FREECAST argv);
+        else {
+            result = Tcl_NewListObj(0, NULL);
+        }
         return result;
     }
     else if (PyUnicode_Check(value)) {