[PATCH 5/8] BUG/MINOR: spoa/python: Cleanup references for failed Module Addobject operations

[Gilchrist Dadaglo]

As per https://docs.python.org/3/c-api/module.html#c.PyModule_AddObject,
references are stolen by the function only for success. We must do
cleanup manually if there is a failure
---
 contrib/spoa_server/ps_python.c | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/contrib/spoa_server/ps_python.c b/contrib/spoa_server/ps_python.c
index fbaa414..12953f3 100644
--- a/contrib/spoa_server/ps_python.c
+++ b/contrib/spoa_server/ps_python.c
@@ -427,8 +427,19 @@ static int ps_python_start_worker(struct worker *w)
        }
 
        spoa_error = PyErr_NewException("spoa.error", NULL, NULL);
+        /* PyModule_AddObject will steal the reference to spoa_error
+        * in case of success only
+        * We need to increment the counters to continue using it
+        * but cleanup in case of failure
+        */
        Py_INCREF(spoa_error);
-       PyModule_AddObject(m, "error", spoa_error);
+       ret = PyModule_AddObject(m, "error", spoa_error);
+       if (ret == -1) {
+               Py_DECREF(m);
+               Py_DECREF(spoa_error);
+               PyErr_Print();
+               return 0;
+       }
 
 
        value = PyLong_FromLong(SPOE_SCOPE_PROC);
@@ -439,54 +450,68 @@ static int ps_python_start_worker(struct worker *w)
 
        ret = PyModule_AddObject(m, "scope_proc", value);
        if (ret == -1) {
+               Py_DECREF(m);
+               Py_DECREF(value);
                PyErr_Print();
                return 0;
        }
 
        value = PyLong_FromLong(SPOE_SCOPE_SESS);
        if (value == NULL) {
+               Py_DECREF(m);
                PyErr_Print();
                return 0;
        }
 
        ret = PyModule_AddObject(m, "scope_sess", value);
        if (ret == -1) {
+               Py_DECREF(m);
+               Py_DECREF(value);
                PyErr_Print();
                return 0;
        }
 
        value = PyLong_FromLong(SPOE_SCOPE_TXN);
        if (value == NULL) {
+               Py_DECREF(m);
                PyErr_Print();
                return 0;
        }
 
        ret = PyModule_AddObject(m, "scope_txn", value);
        if (ret == -1) {
+               Py_DECREF(m);
+               Py_DECREF(value);
                PyErr_Print();
                return 0;
        }
 
        value = PyLong_FromLong(SPOE_SCOPE_REQ);
        if (value == NULL) {
+               Py_DECREF(m);
                PyErr_Print();
                return 0;
        }
 
        ret = PyModule_AddObject(m, "scope_req", value);
        if (ret == -1) {
+               Py_DECREF(m);
+               Py_DECREF(value);
                PyErr_Print();
                return 0;
        }
 
        value = PyLong_FromLong(SPOE_SCOPE_RES);
        if (value == NULL) {
+               Py_DECREF(m);
                PyErr_Print();
                return 0;
        }
 
        ret = PyModule_AddObject(m, "scope_res", value);
        if (ret == -1) {
+               Py_DECREF(m);
+               Py_DECREF(value);
                PyErr_Print();
                return 0;
        }
-- 
2.23.3