Crash report

The following code will causes a segmentation fault:

>>>importdecimal>>>tp=type(decimal.Context().flags)# SignalDict type>>>tp()# Segmentation fault

This code instantiates an object ofSignalDict type (inherited from the base classSignalDictMixin) and tries to print the contents of the object (userepr).

The problem is caused by the following C code, where thesignaldict_repr functionaccesses a null pointer.

staticintsignaldict_init(PyObject*self,PyObject*argsUNUSED,PyObject*kwdsUNUSED){SdFlagAddr(self)=NULL;return0;}...staticPyObject*signaldict_repr(PyObject*self){    ...for (cm=signal_map,i=0;cm->name!=NULL;cm++,i++) {n[i]=cm->fqname;// Access NULL pointer hereb[i]=SdFlags(self)&cm->flag ?"True" :"False";    }    ...}

Your environment

• CPython versions tested on: 3.13.0.0a0, 3.10.2
• Operating system and architecture: Ubuntu 22.04.1 LTS, Windows 11

Linked PRs

• gh-106263: Fix segfault insignaldict_repr #106270
• [3.11] gh-106263: Fix segfault insignaldict_repr in_decimal module (#… #107490
• [3.12] gh-106263: Fix segfault insignaldict_repr in_decimal module (#… #107491