[jseop-lim]

Description

Fixes #1225

When imag is neither a complex nor a string, complex(real, imag) called imag.__float__ before checking that real is a number, so an exception from that call replaced the first-argument TypeError. CPython's complex_new_impl checks the type of real, then of imag, and only then converts real followed by imag (complexobject.c#L945-L1018).

AS-IS

>>> complex({}, RaisingImag())         # RaisingImag.__float__ raises RuntimeError
RuntimeError
>>> complex(RaisingReal(), RaisingImag())  # RaisingReal.__float__ raises KeyError
RuntimeError
>>> complex({}, {})
TypeError: complex() second argument must be a number, not 'dict'

TO-BE

>>> complex({}, RaisingImag())
TypeError: complex() first argument must be a string or a number, not 'dict'
>>> complex(RaisingReal(), RaisingImag())
KeyError
>>> complex({}, {})
TypeError: complex() first argument must be a string or a number, not 'dict'

(matching CPython)

Changes

• Reorder ComplexNewNode.complexFromComplexObject to raise the first-argument error, then the second-argument error, and only then convert real and imag in that order. The other (Object, long|double|PInt) specializations already check real first.
• Add test_create_checks_arguments_before_converting to tests/test_complex.py.

Testing

mx python-jvm on linux-aarch64, then mx graalpytest test_complex.py (11 passed) and test.test_complex from lib-python (35 passed, same as master). The new test fails on the unpatched build. Twelve complex() call shapes, covering __float__, __index__ and __complex__ arguments and imag= alone, now print the same as CPython 3.12.13.