SQL API query with `where column in (null)` causes unexpected panic during rewrite

[tfzrch]

Describe the bug
SQL API is unable to handle where clauses including the condition column in (null). Instead it throws an "Unexpected panic" error.

To Reproduce

Using SQL API, query a column from any Cube using where (<column> is null or <column> in (null) and (1<>1)) as a filter. Should see an error (details below).

Alternatively, a minimal reprex with a fresh installation of Postgres and Cube:

1. Create a fresh Postgres and Cube setup with Docker
2. Add a table to Postgres and insert some data

CREATE TABLE tbl (
  id serial PRIMARY KEY,
  label text
);

INSERT INTO tbl(label) VALUES ('one'), ('two'), (NULL), ('four');

3. Query the database directly: select * from tbl where (label is null or label in (null) and (1<>1)). Should get row 3 returned without error.
4. Create a Cube data model for tbl (schema below)
5. Query the cube using the same SQL syntax
6. See error

Error during rewrite: Unexpected panic. Reason: Unsupported filter scalar: NULL. Please check logs for additional information.

6. Logs show

thread 'tokio-runtime-worker' panicked at /__w/cube/cube/rust/cubesql/cubesql/src/compile/rewrite/rules/filters.rs:3573:18:
Unsupported filter scalar: NULL
SQL API Error: c4df0a8c-46b8-470c-a92f-9c78328ebeca-span-1 (6ms)
--
{
  "sql": "select * from tbl where (label is null or label in (null) and (1<>1))"
}
--
{
  "securityContext": {},
  "appName": "NULL",
  "protocol": "postgres",
  "apiType": "sql"
} 
Error during rewrite: Unexpected panic. Reason: Unsupported filter scalar: NULL. Please check logs for additional information.
Cube SQL Error: undefined 
--
"SELECT * FROM tbl WHERE (label IS NULL OR label IN (NULL) AND (1 <> 1))"
--
{
  "protocol": "postgres",
  "apiType": "sql",
  "appName": "NULL",
  "sanitizedQuery": "SELECT * FROM tbl WHERE (label IS NULL OR label IN (NULL) AND (1 <> 1))"
} 
Error during rewrite: Unexpected panic. Reason: Unsupported filter scalar: NULL. Please check logs for additional information.

Expected behavior
Cube SQL API query should return the same result as direct query to Postgres

Minimally reproducible Cube Schema

cubes:
  - name: tbl
    sql_table: public.tbl
    data_source: default
    dimensions:
      - name: id
        sql: id
        type: number
        primary_key: true

      - name: label
        sql: label
        type: string

Version:
Cube: 1.1.18
Postgres: 16

Additional Context

• Superset native filters generate this SQL when attempting to filter for a null value
• As it's generated I'm not able to use where label is null without the or label in (null) and (1<>1) as a workaround

[mcheshkov]

@tfzrch Can you check it on 1.2.0 or newer?

[tfzrch]

Tested on 1.2.0; it works! Many thanks!