[C++] Regression with compute utf8_*trim functions on macOS.

[asfimport]

import pyarrow as pa
import pyarrow.compute as pc

arr = pa.array(["ab", "ac"])
r = pc.utf8_ltrim(arr, characters="a")
assert r.to_pylist() == ["b", "c"], r
r = pc.utf8_rtrim(arr, characters="b")
assert r.to_pylist() == ["a", "ac"], r

Seems to go awry after the first match.

Environment: macOS 11.5
Reporter: A. Coady / @coady
Assignee: Antoine Pitrou / @pitrou

PRs and other links:

• GitHub Pull Request #10853

_{Note: This issue was originally created as ARROW-13522. Please see the migration documentation for further details.}

[asfimport]

Antoine Pitrou / @pitrou:
I seem to get the correct results here:

>>> import pyarrow as pa, pyarrow.compute as pc
>>> arr = pa.array(["ab", "ac"])
>>> pc.utf8_ltrim(arr, characters="a").to_pylist()
['b', 'c']
>>> pc.utf8_rtrim(arr, characters="b").to_pylist()
['a', 'ac']

Are you expecting something else?

[asfimport]

A. Coady / @coady:
Didn't reproduce on ubuntu; seems to be macOS only. And updated the example.

• macOS 11.5.1
• pyarrow-5.0.0-cp39-cp39-macosx_10_13_x86_64.whl

[asfimport]

Antoine Pitrou / @pitrou:
Ok, it does seem to be completely broken on MacOS :-(

In [1]: import pyarrow as pa

In [2]: import pyarrow.compute as pc

In [3]: arr = pa.array(["ab", "ac"])

In [5]: pc.utf8_ltrim(arr, characters="a")
Out[5]: 
<pyarrow.lib.StringArray object at 0x7fc9d08b3b40>
[
  "",
  ""
]

In [10]: pc.utf8_rtrim(arr, characters="b")
Out[10]: 
<pyarrow.lib.StringArray object at 0x7fc9d06bbb40>
[
  "a",
  "a"
]

[asfimport]

Joris Van den Bossche / @jorisvandenbossche:
Is it a regression compared to 4.0?

[asfimport]

Antoine Pitrou / @pitrou:
Don't know, but it would be nice to fix anyway.

[asfimport]

A. Coady / @coady:
Yes, it worked in 4.0.

[asfimport]

Antoine Pitrou / @pitrou:
Issue resolved by pull request 10853
#10853

[asfimport]

Antoine Pitrou / @pitrou:
This should be fixed now. I encourage you to check using the nightly builds, for example tomorrow:

https://arrow.apache.org/docs/python/install.html#installing-nightly-packages

[asfimport]

Antoine Pitrou / @pitrou:
I've checked that the issue is fixed on an Intel Mac using the latest nightly wheels.