Write chunks with negative zero values and a zero fill value

[bojidar-bg]

Fixes #3144.

Using np.any(self._data) was inspired by how Zarr v2 checks for equality with a falsey fill value.

TODO:

• Add unit tests and/or doctests in docstrings
• Add docstrings and API docs for any new/modified user-facing classes and functions
• New/modified features documented in docs/user-guide/*.rst
• Changes documented as a new file in changes/
• GitHub Actions have all passed
• Test coverage is 100% (Codecov passes)

[bojidar-bg]

Oh, oops, thanks 😅

[d-v-b]

this test failure seems significant: https://github.com/zarr-developers/zarr-python/actions/runs/16172926021/job/45650861381?pr=3216#step:8:420

[dcherian]

this test failure seems significant

Yes looks like this approach doesn't work for complex number types

[d-v-b]

what if we view the array as raw bytes (should be cheap) and compare the raw bytes?

>>> import numpy as np
>>> np.array([0.0]) == np.array([-0.0])
array([ True])
>>> np.array([0.0]).view('V') == np.array([-0.0]).view('V')
array([False])

[bojidar-bg]

I wonder if that would somehow break with floating point subnormal-s and the like. Will have to experiment 🤔