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.
{
    RewriteFunctionToSubcolumnVisitor::Data data{metadata_snapshot};
    RewriteFunctionToSubcolumnVisitor(data).visit(query);
}
std::shared_ptr<ASTFunction> getQuantileFuseCandidate(const String & func_name, std::vector<ASTPtr *> & functions)
{
    if (functions.size() < 2)
        return nullptr;
    const auto & common_arguments = (*functions[0])->as<ASTFunction>()->arguments->children;
    auto func_base = makeASTFunction(GatherFunctionQuantileData::getFusedName(func_name));
    func_base->arguments->children = common_arguments;
    func_base->parameters = std::make_shared<ASTExpressionList>();
    for (const auto * ast : functions)
    {
        assert(ast && *ast);
        const auto * func = (*ast)->as<ASTFunction>();
        assert(func && func->parameters->as<ASTExpressionList>());
        const ASTs & parameters = func->parameters->as<ASTExpressionList &>().children;
        if (parameters.size() != 1)
            return nullptr; 
        func_base->parameters->children.push_back(parameters[0]);
    }
    return func_base;
}
void optimizeFuseQuantileFunctions(ASTPtr & query)