You have to provide the following information whenever possible.

**Describe the bug**
This query fails with the latest stable version 21.5.5.12. It worked with the last stable version 21.4.7.3.

**Does it reproduce on recent release?**
yes

**How to reproduce**
21.5.5.12

```
SELECT
    label,
    number
FROM
(
    SELECT
        'a' AS label,
        number
    FROM
    (
        SELECT number
        FROM numbers(10)
    )
    UNION ALL
    SELECT
        'b' AS label,
        number
    FROM
    (
        SELECT number
        FROM numbers(10)
    )
)
WHERE number IN
(
    SELECT number
    FROM numbers(5)
)
```

**Expected behavior**
Query should run without errors

**Error message and/or stacktrace**
```
Received exception from server (version 21.5.5):
Code: 49. DB::Exception: Received from localhost:9000. DB::Exception: Block structure mismatch in Pipe::unitePipes stream: different names of columns:
label String String(size = 0), number UInt64 UInt64(size = 0), 'b' String Const(size = 0, String(size = 1))
label String String(size = 0), number UInt64 UInt64(size = 0), 'a' String Const(size = 0, String(size = 1)).
```

{
    Node * predicate = const_cast<Node *>(tryFindInIndex(filter_name));
    if (!predicate)
            throw Exception(ErrorCodes::LOGICAL_ERROR,
                            "Index for ActionsDAG does not contain filter column name {}. DAG:\n{}",
                            filter_name, dumpDAG());
    
    
    if (predicate->type == ActionType::COLUMN)
        return nullptr;
    std::unordered_set<const Node *> allowed_nodes;
    
    {
        std::unordered_map<std::string_view, std::list<const Node *>> inputs_map;
        for (const auto & input : inputs)
            inputs_map[input->result_name].emplace_back(input);
        for (const auto & name : available_inputs)
        {
            auto & inputs_list = inputs_map[name];
            if (inputs_list.empty())
                continue;
            allowed_nodes.emplace(inputs_list.front());
            inputs_list.pop_front();
        }
    }
    auto conjunction = getConjunctionNodes(predicate, allowed_nodes);
    auto actions = cloneActionsForConjunction(conjunction.allowed, all_inputs);
    if (!actions)
        return nullptr;