Always reproduced:

```
milovidov-desktop :) create table table_map (a Map(String, String), b String) engine = MergeTree() order by a;

CREATE TABLE table_map
(
    `a` Map(String, String),
    `b` String
)
ENGINE = MergeTree
ORDER BY a

Query id: 8f8120c1-c165-452a-815f-2bcae3957e2a

Ok.

0 rows in set. Elapsed: 0.002 sec. 

milovidov-desktop :) SELECT b FROM table_map WHERE a = map('name', NULL, '', NULL)

SELECT b
FROM table_map
WHERE a = {'name', NULL, '', NULL}
```
res_indexes = col_low_cardinality->getIndexesPtr();
                    tmp_rows_count = arg.column->size();
                }
                
                converted_column = wrapper(args, res_type, nullable_source, tmp_rows_count);
            }
            if (to_low_cardinality)
            {
                auto res_column = to_low_cardinality->createColumn();
                auto * col_low_cardinality = typeid_cast<ColumnLowCardinality *>(res_column.get());
                if (from_low_cardinality && !src_converted_to_full_column)
                {
                    col_low_cardinality->insertRangeFromDictionaryEncodedColumn(*converted_column, *res_indexes);
                }
                else
                    col_low_cardinality->insertRangeFromFullColumn(*converted_column, 0, converted_column->size());
                return res_column;
            }
            else if (!src_converted_to_full_column)
                return converted_column->index(*res_indexes, 0);
            else
                return converted_column;
        };
    }
    WrapperType prepareRemoveNullable(const DataTypePtr & from_type, const DataTypePtr & to_type, bool skip_not_null_check) const
    {
        
        bool source_is_nullable = from_type->isNullable();
        bool result_is_nullable = to_type->isNullable();
        auto wrapper = prepareImpl(removeNullable(from_type), removeNullable(to_type), result_is_nullable);