**Describe what's wrong**

Query with rollup using same selected field name as the name of underlying column reports structure mismatch

**Does it reproduce on recent release?**

yes

**How to reproduce**

`21.9.2.17`

```sql
CREATE TABLE test
(
    `d` DateTime,
    `a` LowCardinality(String),
    `b` UInt64
)
ENGINE = MergeTree
PARTITION BY toDate(d)
ORDER BY d;

SELECT *
FROM (
    SELECT
        a,
        max((d, b)).2 AS value
    FROM test
    GROUP BY rollup(a)
)
WHERE a <> '';
```

**Expected behavior**

This used to return an ok result on v21.8

**Error message and/or stacktrace**

> Code: 352. DB::Exception: Block structure mismatch in (columns with identical name must have identical structure) stream: different columns:
> notEquals(a, '') LowCardinality(UInt8) ColumnLowCardinality(size = 0, UInt8(size = 0), ColumnUnique(size = 1, UInt8(size = 1)))
> notEquals(a, '') LowCardinality(UInt8) Const(size = 0, ColumnLowCardinality(size = 1, UInt8(size = 1), ColumnUnique(size = 2, UInt8(size = 2)))). (AMBIGUOUS_COLUMN_NAME) (version 21.9.2.17 (official build))



initSettings();
    const Settings & settings = context->getSettingsRef();
    if (settings.max_subquery_depth && options.subquery_depth > settings.max_subquery_depth)
        throw Exception("Too deep subqueries. Maximum: " + settings.max_subquery_depth.toString(),
            ErrorCodes::TOO_DEEP_SUBQUERIES);
    bool has_input = input || input_pipe;
    if (input)
    {
        
        source_header = input->getHeader();
    }
    else if (input_pipe)
    {
        
        source_header = input_pipe->getHeader();
    }
    
    if (!options.is_subquery)
    {
        if (context->getSettingsRef().enable_global_with_statement)
            ApplyWithAliasVisitor().visit(query_ptr);
        ApplyWithSubqueryVisitor().visit(query_ptr);
    }
    JoinedTables joined_tables(getSubqueryContext(context), getSelectQuery(), options.with_all_cols);
    bool got_storage_from_query = false;
    if (!has_input && !storage)
    {
        storage = joined_tables.getLeftTableStorage();
        got_storage_from_query = true;
    }