PG_FINALLY

This gives an alternative way of catching exceptions, for the common
case where the cleanup code is the same in the error and non-error
cases.  So instead of

    PG_TRY();
    {
        ... code that might throw ereport(ERROR) ...
    }
    PG_CATCH();
    {
        cleanup();
	PG_RE_THROW();
    }
    PG_END_TRY();
    cleanup();

one can write

    PG_TRY();
    {
        ... code that might throw ereport(ERROR) ...
    }
    PG_FINALLY();
    {
        cleanup();
    }
    PG_END_TRY();

Discussion: https://www.postgresql.org/message-id/flat/95a822c3-728b-af0e-d7e5-71890507ae0c%402ndquadrant.com

src/pl/plpython/plpy_exec.c

@@ -403,18 +403,13 @@ PLy_exec_trigger(FunctionCallInfo fcinfo, PLyProcedure *proc)
 			}
 		}
 	}
-	PG_CATCH();
+	PG_FINALLY();
 	{
 		Py_XDECREF(plargs);
 		Py_XDECREF(plrv);
-
-		PG_RE_THROW();
 	}
 	PG_END_TRY();
 
-	Py_DECREF(plargs);
-	Py_DECREF(plrv);
-
 	return rv;
 }
 
@@ -1052,15 +1047,12 @@ PLy_procedure_call(PLyProcedure *proc, const char *kargs, PyObject *vargs)
 		 */
 		Assert(list_length(explicit_subtransactions) >= save_subxact_level);
 	}
-	PG_CATCH();
+	PG_FINALLY();
 	{
 		PLy_abort_open_subtransactions(save_subxact_level);
-		PG_RE_THROW();
 	}
 	PG_END_TRY();
 
-	PLy_abort_open_subtransactions(save_subxact_level);
-
 	/* If the Python code returned an error, propagate it */
 	if (rv == NULL)
 		PLy_elog(ERROR, NULL);