id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,active_lock_reason,draft,pull_request,body,reactions,performed_via_github_app,state_reason,repo,type
1608352581,I_kwDOAMm_X85f3YNF,7581,xr.where loses attributes despite keep_attrs=True,500246,closed,0,,,1,2023-03-03T10:14:34Z,2023-04-06T01:58:45Z,2023-04-06T01:58:45Z,CONTRIBUTOR,,,,"### What happened?

 I'm using `xarray.where` to mask data: `xr.where(ds == ds.attrs[""_FillValue""], nan, ds)`.  This loses the attributes on `ds` even if I pass `keep_attrs=True`.

### What did you expect to happen?

I expect that if I use `keep_attrs=True`, either via `xr.set_options` or directly passed to `xr.where`, that attributes on the dataset are retained.

### Minimal Complete Verifiable Example

```Python
import xarray as xr
a = xr.DataArray([0], attrs={""a"": ""b""})
with xr.set_options(keep_attrs=True):
        a2 = xr.where(a==0, 0, a, keep_attrs=True)
print(a2.attrs)
```


### MVCE confirmation

- [X] Minimal example — the example is as focused as reasonably possible to demonstrate the underlying issue in xarray.
- [X] Complete example — the example is self-contained, including all data and the text of any traceback.
- [X] Verifiable example — the example copy & pastes into an IPython prompt or [Binder notebook](https://mybinder.org/v2/gh/pydata/xarray/main?urlpath=lab/tree/doc/examples/blank_template.ipynb), returning the result.
- [X] New issue — a search of GitHub Issues suggests this is not a duplicate.

### Relevant log output

```Python
{}
```


### Anything else we need to know?

I can make a workaround by turning the logic around, such as `xr.where(a!=0, a, 0)`, which does retain attributes.

The workaround works in this case, but `a!=0` is not always the same as `a==0`, so it would be preferable if the attributes were retained either way.

### Environment

<details>

INSTALLED VERSIONS
------------------
commit: None
python: 3.11.0 | packaged by conda-forge | (main, Jan 14 2023, 12:27:40) [GCC 11.3.0]
python-bits: 64
OS: Linux
OS-release: 5.3.18-150300.59.76-default
machine: x86_64
processor: x86_64
byteorder: little
LC_ALL: None
LANG: en_GB.UTF-8
LOCALE: ('en_GB', 'UTF-8')
libhdf5: 1.12.2
libnetcdf: 4.9.1

xarray: 2023.2.0
pandas: 1.5.3
numpy: 1.24.2
scipy: 1.10.1
netCDF4: 1.6.2
pydap: None
h5netcdf: 1.1.0
h5py: 3.8.0
Nio: None
zarr: 2.13.6
cftime: 1.6.2
nc_time_axis: None
PseudoNetCDF: None
rasterio: 1.3.6
cfgrib: None
iris: None
bottleneck: 1.3.6
dask: 2023.2.1
distributed: 2023.2.1
matplotlib: 3.7.0
cartopy: 0.21.1
seaborn: None
numbagg: None
fsspec: 2023.1.0
cupy: None
pint: 0.20.1
sparse: None
flox: None
numpy_groupies: None
setuptools: 67.4.0
pip: 23.0.1
conda: None
pytest: 7.2.1
mypy: None
IPython: 8.7.0
sphinx: 5.3.0

</details>
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