[ARROW-14795] [C++] Replace With Mask not correctly replacing nulls

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 7.0.0
• Component/s: C++
• Labels: kernel pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/30330
• Assignee: Alvin Chunga Mamani
• Reporter: Alvin Chunga Mamani
• Created: 22/Nov/21 20:50
• Updated: 11/Jan/23 08:42
• Resolved: 29/Nov/21 17:09

Description

I'm working in ARROW-1699 and using the method ReplaceWithArrayMask for replace the nulls using a generated mask, but the method gave me unexpected results when the input Array contains nulls and this nulls are replaced with values.
When testing this special Test on vector_test_replace_test.cc

this->Assert(ReplaceWithMask, this->array("[1, null, 1]"),
   this->mask("[false, true, false]"),
   this->array("[7]"),
   this->array("[1, 7, 1]"));

The result is:

Actual:
[
1,
null,
1
]

And  debugging the code, the output values is correct, but the null_bitmap isn't updated and keep the original null_bitmap
In the file vector_replace.cc  on line 202, the bitmap is updated only for turnoff the null replacement values

This is and expected behavior or an issue on ReplaceWithArrayMask ? 

Issue Links

• links to: GitHub Pull Request #11759