Fatal Python error: none_dealloc: deallocating None when getting commit author

[siscia]

Hello everybody, and thanks for maintaining this repository.

I am reporting a runtime error Fatal Python error: none_dealloc: deallocating None

I am iterating over commits of a repository and getting information about the commiter:

import pygit2 # type: ignore

# this is a git clone of
# git@github.com:facebook/react.git
repo_path = "tests/react"

repo = pygit2.Repository(repo_path)

commits = repo.walk(repo.head.target, pygit2.GIT_SORT_REVERSE)

# we are missing what is happening at the first commit
for commit in commits:
    author = commit.author
    print(f"{commit.id=}")
    print(f"{author=}")

The execution terminates with:

... more logs line...
commit.id=eb056fcf5d12f100e4f8df700b634d3c4cc5f9ba
author=pygit2.Signature('Paul O’Shannessy', 'paul@oshannessy.com', 1439962431, 4294966876, None)
commit.id=ec9b866bc0fa4118f0b3750589e26ed851ef97bd
author=pygit2.Signature('Paul O’Shannessy', 'paul@oshannessy.com', 1439946313, 4294966876, None)
commit.id=50adfeb4217a6086fe7d9c4be5d9db732614106e
author=pygit2.Signature('Paul O’Shannessy', 'paul@oshannessy.com', 1440001562, 4294966876, None)
commit.id=1e10bb5923b32ab3b6c86c65c7ed18f693056da5
Fatal Python error: none_dealloc: deallocating None
Python runtime state: initialized

Current thread 0x00007f423d6f21c0 (most recent call first):
  File "/home/simo/projects/codedigger/repro.py", line 14 in <module>

Extension modules: pygit2._pygit2, _cffi_backend (total: 2)
Aborted (core dumped)

It is not deterministic when it terminates, and it always terminates at a different commit.

[siscia]

It is not super clear to me this call

pygit2/src/signature.c

Line 248 in efa451d

encoding = Py_None;

As I would expect that we need to increase the reference counting for that none.

[siscia]

Yep, it was that!

Preparing PR

[jdavid]

Fixed with #1162