GH-140058: Clear key and value if PyTuple_New fails in dictiter_iternextitem

[sergey-miryanov]

Following code should decref key and value if PyTuple_New fails:

cpython/Objects/dictobject.c

Lines 5720 to 5726 in 6481539

	else {
	result = PyTuple_New(2);
	if (result == NULL)
	return NULL;
	PyTuple_SET_ITEM(result, 0, key);
	PyTuple_SET_ITEM(result, 1, value);
	}

• Issue: Possible memory leak on fail path in dictiter_iternextitem #140058

[sergey-miryanov]

I believe this should skip news.
Should be backported to 3.13 and 3.14.

[picnixz]

@eendebakpt Couldn't we actually use the PyTuple_FromArray API here? If so, I would suggest fixing the refleak as part of the change (I don't know if we gain something)

[eendebakpt]

@eendebakpt Couldn't we actually use the PyTuple_FromArray API here? If so, I would suggest fixing the refleak as part of the change (I don't know if we gain something)

The code here steals the references. When using the PyPuple_FromArray we would have additional increfs/decrefs. The PyTuple_MakePairSteal would work though.

Update: If this is to be backported, I prefer to use a direct approach (as in this PR). Conversion to PyTuple_MakePairSteal can be a followup PR.

[miss-islington-app]

Thanks @sergey-miryanov for the PR, and @kumaraditya303 for merging it 🌮🎉.. I'm working now to backport this PR to: 3.13, 3.14.
🐍🍒⛏🤖

[bedevere-app]

GH-140107 is a backport of this pull request to the 3.14 branch.

[bedevere-app]

GH-140108 is a backport of this pull request to the 3.13 branch.

[sergey-miryanov]

Thanks all!