Fix 'IS NOT DISTINCT FROM' not working in JOIN when nulls are used

[codluca]

Fix 'IS NOT DISTINCT FROM' not working in JOIN when nulls are the only value.

Fixes issue: #26257

Description

The changes try to enable Domain with only null value to be used.

Modify JoinDomainBuilder to take into consideration the nulls from the value blocks.

Additional context and related issues

Release notes

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## Section
* Fix some things. ({issue}`26257`)

[codluca]

@raunaqmorarka The pull request is ready.
There is a failed check (ci / test plugin/trino-pinot), but it is something random, not related to the code changes.

[Copilot]

Pull Request Overview

This PR fixes a bug where 'IS NOT DISTINCT FROM' operations in JOIN clauses were not working correctly when null values were involved. The issue occurred because the Domain building logic was incorrectly treating null-only domains as empty domains.

• Modified JoinDomainBuilder to properly handle null values by tracking when nulls are present in value blocks
• Updated Domain creation logic to include null allowance when nulls are detected in the data
• Fixed DynamicFilters to correctly handle null-allowed domains in IS NOT DISTINCT FROM comparisons

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
TestJoinIsNotDistinct.java	Adds comprehensive test coverage for IS NOT DISTINCT FROM with various null scenarios
TestDynamicFilterSourceOperator.java	Updates existing tests to expect correct null-allowed domain behavior
DynamicFilters.java	Fixes domain comparison logic to properly handle null allowance in IS NOT DISTINCT FROM operations
JoinDomainBuilder.java	Adds null tracking and removes incorrect comments about join behavior with nulls

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[martint]

Use QueryAssertions instead of AbstractTestQueryFramework. Take a look at the tests under io.trino.sql.query.

[codluca]

If on master (without the fix) I add this test to io.trino.sql.query.TestJoin, it will succeed:

    @Test
    public void testJoinWithIsNotDistinctFromOnNullsInMemory()
    {
        assertThat(assertions.query(
                """
                WITH
                  a AS (SELECT k1, k2 FROM (VALUES (1, NULL)) AS t(k1, k2)),
                  b AS (SELECT k1, k2 FROM (VALUES (1, NULL)) AS t(k1, k2))
                SELECT *
                FROM a
                INNER JOIN b ON a.k1 IS NOT DISTINCT FROM b.k1
                            AND a.k2 IS NOT DISTINCT FROM b.k2
                """))
                .matches("VALUES (1, NULL, 1, NULL)");
    }

The code doesn't follow the same path, using the JoinDomainBuilder, if the temporary tables are used. The Domain is build differently.
I added the extra test from below (testJoinWithIsNotDistinctFromOnNullsInMemory) just for the future, as the test was working before the fix.

[martint]

You should be able to use temporary tables with QueryAssertions, as well. You just need to initialize QueryAssertions with the memory plugin and populate the tables for the test.

[codluca]

Replaced with QueryAssertions