[Bug]: collections._tuplegetter accepts fewer than two arguments and keyword arguments #1249

Describe the bug

_collections._tuplegetter treats index and doc as optional keyword-capable parameters. A call with fewer than two arguments builds a getter for index 0, while CPython requires exactly two positional arguments and rejects keywords.

Operating system

macOS

CPU architecture

ARM64

GraalPy version

master a3009f9 (Python 3.13.14); also reproduced on 25.0.2 (Python 3.12.8)

JDK version

No response

Context configuration

No response

Steps to reproduce

import collections
print(type(collections._tuplegetter(0)))

GraalPy master a3009f9:

<class '_collections._tuplegetter'>

Expected behavior

CPython 3.13.14 (same on 3.12.13):

TypeError: _tuplegetter expected 2 arguments, got 1

Stack trace

Additional context

_tuplegetter() with no arguments also succeeds, and _tuplegetter(0, doc=None) and _tuplegetter(index=0, doc=None) succeed where CPython raises TypeError: _tuplegetter() takes no keyword arguments.

Root Cause

The tp_new of TupleGetterNode declares @SlotSignature(name = J_TUPLE_GETTER, parameterNames = {"cls", "index", "doc"}) with no minimum or positional-only count (TupleGetterBuiltins.java#L97-L99), so both arguments are optional and can be passed by keyword. CPython's tuplegetter_new rejects keywords and then calls _PyArg_CheckPositional("_tuplegetter", nargs, 2, 2) (_collectionsmodule.c.h#L607-L613).

Fix Suggestion

Add minNumOfPositionalArgs = 3, numOfPositionalOnlyArgs = 3 to that @SlotSignature.