Benchmark test fails for large numbers in `decimal` module

[CharlieZhao95]

Bug report

Checklist

• I am confident this is a bug in CPython, not a bug in a third-party project
• I have searched the CPython issue tracker,
  and am confident this bug has not been reported before

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux

Output from running 'python -VV' on the command line:

Python 3.13.0a0 (heads/demo/parser:a794ebeb02, Aug 22 2023, 11:44:58) [GCC 11.3.0]

A clear and concise description of the bug:

There are some tests in the decimal module related to large numbers, they may fail due to the patch of CVE-2020-10735 (large int<->str conversions). Here is a benchmark in decimal.

cd ./Modules/_decimal/tests
../../../python bench.py

Output:

...
# ======================================================================
#                               Factorial
# ======================================================================

n = 100000

cdecimal:
calculation time: 0.942886s
conversion time: 0.002155s

Traceback (most recent call last):
  File "/home/github/cpython/Modules/_decimal/tests/bench.py", line 121, in <module>
    sy = str(y)
         ^^^^^^
ValueError: Exceeds the limit (4300 digits) for integer string conversion; use sys.set_int_max_str_digits() to increase the limit

Linked PRs

• gh-108346: Fix failed benchmark in decimal #108353

[CharlieZhao95]

This problem is not difficult, I prefer to add a decorator to change the limit of the maximum digits that can be converted within the function, while not affecting the external scope.

Note: this is not the only test case that fails (e.g. deccheck.py).

[gpshead]

merged, thanks! I'm not going to bother backporting this, it doesn't seem to be run automatically and the code is mostly of interest to people working on the decimal implementation performance itself which doesn't happen in release branches anyways.