If [monitoring](https://github.com/python/cpython/blob/ac12de2e6a6f5c1da83de0412bb7d03c28fdab63/Python/instrumentation.c#L837) variable is equal to NULL then we'll get segmentation fault in [line 843](https://github.com/python/cpython/blob/ac12de2e6a6f5c1da83de0412bb7d03c28fdab63/Python/instrumentation.c#L843) since [monitoring = code->_co_monitoring](https://github.com/python/cpython/blob/ac12de2e6a6f5c1da83de0412bb7d03c28fdab63/Python/instrumentation.c#L835). Otherwise, the if statement is incorrect. <!-- gh-linked-prs --> ### Linked PRs * gh-131765 <!-- /gh-linked-prs -->