Describe the issue:

np.dot result changes based on shape when the inputs containsnan

Reproduce the code example:

import numpy as np

print(np.dot(np.array([[np.nan]]), np.array(0.)))
print(np.dot(np.array([[np.nan, np.nan]]), np.array(0.)))

Error message:

[[nan]]
[[0. 0.]]

Python and NumPy Versions:

2.1.0
3.10.12 (main, Jul 29 2024, 16:56:48) [GCC 11.4.0]

Runtime Environment:

[{'numpy_version': '2.1.0',
'python': '3.10.12 (main, Jul 29 2024, 16:56:48) [GCC 11.4.0]',
'uname': uname_result(system='Linux', node='60a9b3769f7e', release='6.8.0-49-generic', version='#49~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Wed Nov 6 17:42:15 UTC 2', machine='x86_64')},
{'simd_extensions': {'baseline': ['SSE', 'SSE2', 'SSE3'],
'found': ['SSSE3',
'SSE41',
'POPCNT',
'SSE42',
'AVX',
'F16C',
'FMA3',
'AVX2'],
'not_found': ['AVX512F',
'AVX512CD',
'AVX512_KNL',
'AVX512_KNM',
'AVX512_SKX',
'AVX512_CLX',
'AVX512_CNL',
'AVX512_ICL']}},
{'architecture': 'Haswell',
'filepath': '/usr/local/lib/python3.10/dist-packages/numpy.libs/libscipy_openblas64_-ff651d7f.so',
'internal_api': 'openblas',
'num_threads': 24,
'prefix': 'libscipy_openblas',
'threading_layer': 'pthreads',
'user_api': 'blas',
'version': '0.3.27'}]

Context for the issue:

This issue may be related to two previous issues in 2019:

1. np.dot(0, inf) result changes based on shape
2. BUG: Dot product does not check for floating point warning flags