BUG/MEDIUM: spoa/python: Fixing PyObject_Call positional arguments

As per https://docs.python.org/3/c-api/object.html#c.PyObject_Call,
positional arguments should be an empty tuple when not used.
Previously the code had a dictionary instead of tuple. This commit is to
fix it and use tuple to avoid unexpected consequences

This patch must be backported as far as 2.0.

diff --git a/contrib/spoa_server/ps_python.c b/contrib/spoa_server/ps_python.c
index f2ddc165fd8ffa035ea9253e2e9bbeb1925f6805..20861d6e37832bd4559ccbeff943ef86e5100b93 100644 (file)
--- a/contrib/spoa_server/ps_python.c
+++ b/contrib/spoa_server/ps_python.c
@@ -43,7 +43,7 @@ static PyObject *module_ipaddress;
 static PyObject *ipv4_address;
 static PyObject *ipv6_address;
 static PyObject *spoa_error;
-static PyObject *empty_array;
+static PyObject *empty_tuple;
 static struct worker *worker;
 
 static int ps_python_start_worker(struct worker *w);
@@ -522,8 +522,8 @@ static int ps_python_start_worker(struct worker *w)
                return 0;
        }
 
-       empty_array = PyDict_New();
-       if (empty_array == NULL) {
+       empty_tuple = PyTuple_New(0);
+       if (empty_tuple == NULL) {
                PyErr_Print();
                return 0;
        }
@@ -710,7 +710,7 @@ static int ps_python_exec_message(struct worker *w, void *ref, int nargs, struct
                                PyErr_Print();
                                return 0;
                        }
-                       value = PyObject_Call(func, empty_array, ip_dict);
+                       value = PyObject_Call(func, empty_tuple, ip_dict);
                        Py_DECREF(func);
                        Py_DECREF(ip_dict);
                        break;
@@ -780,7 +780,7 @@ static int ps_python_exec_message(struct worker *w, void *ref, int nargs, struct
                return 0;
        }
 
-       result = PyObject_Call(python_ref, empty_array, fkw);
+       result = PyObject_Call(python_ref, empty_tuple, fkw);
        Py_DECREF(fkw);
        if (result == NULL) {
                PyErr_Print();