Bug #120034 Wrong Results with LOG(1, N) <=> NULL: UNIQUE Constraint Causes Incorrect Row Deduplication

Description:
Two tables containing identical data produce different query results depending on whether a `UNIQUE` constraint is defined on column `c0`.

In both cases, column `c0` contains only `NULL` values. The query compares `LOG(1, N)` (where N is any positive number) with `c0` using the NULL-safe equality operator `<=>`.

`LOG(1, N)` evaluates to `NULL` for any valid N, because logarithm base 1 is mathematically undefined (1 raised to any power always equals 1). Therefore, the predicate `LOG(1, N) <=> c0` should evaluate to `TRUE` for all rows where `c0 IS NULL`, since `<=>` returns `TRUE` when both operands are `NULL`.

When the `UNIQUE` constraint is present, the query incorrectly returns only one row.  
When the constraint is removed, the query correctly returns two rows.

The issue can be reproduced with various `LOG(1, N)` expressions, including `LOG(1, 1)` and `LOG(1, 2)`.

How to repeat:
Case 1: Table with `UNIQUE` constraint

```sql
DROP DATABASE IF EXISTS test;
CREATE DATABASE test;
USE test;

CREATE TABLE t0(
  c0 DOUBLE UNIQUE,
  c1 VARCHAR(500)
);

INSERT INTO t0(c1) VALUES("1");
INSERT INTO t0(c1) VALUES("2");

SELECT 1 AS c30
FROM t0 AS tom24
WHERE LOG(1,2) <=> tom24.c0
LIMIT 42;
```

Result:

```
+-----+
| c30 |
+-----+
|   1 |
+-----+
1 row in set, 3 warnings
```

Case 2: Table without `UNIQUE` constraint (same data)

```sql
DROP DATABASE IF EXISTS test;
CREATE DATABASE test;
USE test;

CREATE TABLE t0(
  c0 DOUBLE,
  c1 VARCHAR(500)
);

INSERT INTO t0(c1) VALUES("1");
INSERT INTO t0(c1) VALUES("2");

SELECT 1 AS c30
FROM t0 AS tom24
WHERE LOG(1,2) <=> tom24.c0
LIMIT 42;
```

Result:

```
+-----+
| c30 |
+-----+
|   1 |
|   1 |
+-----+
2 rows in set, 1 warning
```

The two tables contain identical data, so the query result should return the same number of rows.

Thank you for the bug report.
Verified as described.