Incorrect slot check: typo in `__dictoffset__`

[sobolevn]

Bug report

I made a typo that made it into the final code: https://github.com/python/cpython/blob/00ffdf27367fb9aef247644a96f1a9ffb5be1efe/Lib/dataclasses.py#L1211-L1212

It should had been __dictoffset__ not __dictrefoffset__.

Fixing plan:

• Add tests for C types with __dictoffset__, so it won't happen again :)
• Fix the typo

Linked PRs

• gh-123941
• gh-123991
• gh-123992

[picnixz]

Out of curiosity... how did you find it?

[sobolevn]

I have a telegram channel, where I post different Python-related posts. Today I posted about how slots work in dataclasses. And one of my readers found this typo :)