sudo_module_register_loghandler: clear sudo_type_LogHandler on error

Also add comments about PyModule_AddObject stealing a ref on success.

plugins/python/python_baseplugin.c

@@ -74,6 +74,7 @@ sudo_module_register_baseplugin(PyObject *py_module)
         goto cleanup;
     }
 
+    // PyModule_AddObject steals a reference to py_class on success
     Py_INCREF(py_class);
     rc = SUDO_RC_OK;
 

plugins/python/python_convmessage.c

@@ -91,6 +91,7 @@ sudo_module_register_conv_message(PyObject *py_module)
         goto cleanup;
     }
 
+    // PyModule_AddObject steals the reference to py_class on success
     Py_INCREF(py_class);
     rc = SUDO_RC_OK;
 

plugins/python/python_loghandler.c

@@ -148,9 +148,12 @@ sudo_module_register_loghandler(PyObject *py_module)
     if (sudo_type_LogHandler == NULL)
         goto cleanup;
 
-    if (PyModule_AddObject(py_module, "LogHandler", sudo_type_LogHandler) < 0)
+    if (PyModule_AddObject(py_module, "LogHandler", sudo_type_LogHandler) < 0) {
+	Py_CLEAR(sudo_type_LogHandler);
         goto cleanup;
+    }
 
+    // PyModule_AddObject steals a reference to sudo_type_LogHandler on success
     Py_INCREF(sudo_type_LogHandler);
 
 cleanup:

plugins/python/sudo_python_module.c

@@ -479,7 +479,6 @@ sudo_module_register_enum(PyObject *py_module, const char *enum_name, PyObject *
         return;
 
     PyObject *py_enum_class = NULL;
-    {
     PyObject *py_enum_module = PyImport_ImportModule("enum");
     if (py_enum_module == NULL) {
 	Py_CLEAR(py_constants_dict);
@@ -492,15 +491,14 @@ sudo_module_register_enum(PyObject *py_module, const char *enum_name, PyObject *
 
     Py_CLEAR(py_constants_dict);
     Py_CLEAR(py_enum_module);
-    }
 
     if (py_enum_class == NULL) {
         debug_return;
     }
 
+    // PyModule_AddObject steals the reference to py_enum_class on success
     if (PyModule_AddObject(py_module, enum_name, py_enum_class) < 0) {
         Py_CLEAR(py_enum_class);
-        debug_return;
     }
 
     debug_return;