bpo-1635741: Fix ref leak in _PyWarnings_Init() error path (GH-23151)

Replace PyModule_AddObject() with PyModule_AddObjectRef() in the
_warnings module to fix a reference leak on error.

Use also PyModule_AddObjectRef() in importdl.c.

1 files changed, 3 insertions, 8 deletions

diff --git a/Python/_warnings.c b/Python/_warnings.c
index 3c048af419..e42b7c3be3 100644
--- a/Python/_warnings.c
+++ b/Python/_warnings.c
@@ -1395,18 +1395,13 @@ _PyWarnings_Init(void)
         goto error;
     }
 
-    Py_INCREF(st->filters);
-    if (PyModule_AddObject(m, "filters", st->filters) < 0) {
+    if (PyModule_AddObjectRef(m, "filters", st->filters) < 0) {
         goto error;
     }
-
-    Py_INCREF(st->once_registry);
-    if (PyModule_AddObject(m, "_onceregistry", st->once_registry) < 0) {
+    if (PyModule_AddObjectRef(m, "_onceregistry", st->once_registry) < 0) {
         goto error;
     }
-
-    Py_INCREF(st->default_action);
-    if (PyModule_AddObject(m, "_defaultaction", st->default_action) < 0) {
+    if (PyModule_AddObjectRef(m, "_defaultaction", st->default_action) < 0) {
         goto error;
     }