Always reproduced (ClickHouse server version 22.3.2.1):
`
udf code, python version 3.9.6
#!/usr/bin/python

import sys
import time

if __name__ == '__main__':
    for line in sys.stdin:
        print("Python4 " + line, end='')
        sys.stdout.flush()
`

SELECT test_function_python('clickhouse')

Query id: 57da3834-1238-4da6-a984-48d4c1bb4a04

┌─test_function_python('clickhouse')─┐
│ Python4 clickhouse                 │
└────────────────────────────────────┘

1 rows in set. Elapsed: 0.001 sec.

SELECT test_function_python('clickhouse') AS uuu
GROUP BY uuu

Query id: c14131e5-e7aa-4585-a9f5-8e4b3e29fe44


0 rows in set. Elapsed: 0.002 sec.

Received exception from server (version 22.3.2):
Code: 46. DB::Exception: Received from 10.254.134.108:9000. DB::Exception: Unknown function test_function_python. (UNKNOWN_FUNCTION)


SELECT uuu
FROM
(
    SELECT test_function_python('clickhouse') AS uuu
) AS tmp
GROUP BY uuu

Query id: 20ca737b-35e1-418a-ab8e-2a296ac44e28

┌─uuu────────────────┐
│ Python4 clickhouse │
└────────────────────┘

1 rows in set. Elapsed: 0.002 sec.
{
    GatherFunctionQuantileVisitor::Data data{};
    GatherFunctionQuantileVisitor(data).visit(query);
    for (auto & candidate : data.fuse_quantile)
    {
        String func_name = candidate.first;
        auto & args_to_functions = candidate.second;
        
        for (auto it : args_to_functions.arg_map_function)
        {
            std::vector<ASTPtr *> & functions = it.second;
            auto func_base = getQuantileFuseCandidate(func_name, functions);
            if (!func_base)
                continue;
            for (size_t i = 0; i < functions.size(); ++i)
            {
                std::shared_ptr<ASTFunction> ast_new = makeASTFunction("arrayElement", func_base, std::make_shared<ASTLiteral>(i + 1));
                if (const auto & alias = (*functions[i])->tryGetAlias(); !alias.empty())
                    ast_new->setAlias(alias);
                *functions[i] = ast_new;
            }
        }
    }
}
}
void TreeOptimizer::optimizeIf(ASTPtr & query, Aliases & aliases, bool if_chain_to_multiif)