Describe the issue:

For object arrays x, I expected vecdot to follow a definition like np.sum(x*x), but this doesn't seem to hold when the length along axis is 0. In this case, the result is None instead of 0.

Reproduce the code example:

import numpy as np
x = np.empty((0,), dtype=object)
np.vecdot(x, x)  # None
x = np.empty((1, 0), dtype=object)
np.vecdot(x, x)  # array([None], dtype=object)

Error message:

Python and NumPy Versions:

2.3.5
3.13.12 | packaged by conda-forge | (main, Feb 5 2026, 05:41:12) [MSC v.1944 64 bit (AMD64)]

Runtime Environment:

No response

How does this issue affect you or how did you find it:

Discovered in the context of running https://github.com/mdhaber/mparray/ against array-api-tests. I can work around it by adding a special case, but it would be nice to have it fixed.