**Describe what's wrong**

Selecting from a Buffer table with ORDER BY <col> DESC clause returns wrong rows, and the returned rows are not ordered.

**Does it reproduce on recent release?**

Tested version: 22.7.2.15

**How to reproduce**

* Which ClickHouse server version to use
22.7.2.15
* `CREATE TABLE` statements for all tables involved

        CREATE TABLE mydb.mytable_stored
        (
            `a` UInt8
        )
        ENGINE = MergeTree
        ORDER BY a;

        CREATE TABLE mydb.mytable
        (
            `a` UInt8
        )
        ENGINE = Buffer('mydb', 'mytable_stored', 4, 600, 3600, 10, 100, 10000, 10000000);

* Sample data for all these tables
Note: rows must be inserted one-by-one:

        INSERT INTO mydb.mytable VALUES (0);
        INSERT INTO mydb.mytable VALUES (1);
        INSERT INTO mydb.mytable VALUES (2);
        INSERT INTO mydb.mytable VALUES (3);
        INSERT INTO mydb.mytable VALUES (4);
        INSERT INTO mydb.mytable VALUES (5);
        INSERT INTO mydb.mytable VALUES (6);
        INSERT INTO mydb.mytable VALUES (7);
        INSERT INTO mydb.mytable VALUES (8);
        INSERT INTO mydb.mytable VALUES (9);

* Queries to run that lead to unexpected result

        SELECT a FROM mydb.mytable ORDER BY a DESC LIMIT 5;
        ┌─a─┐
        │ 3 │
        │ 7 │
        └───┘
        ┌─a─┐
        │ 2 │
        │ 6 │
        └───┘
        ┌─a─┐
        │ 1 │
        └───┘
        5 rows in set. Elapsed: 0.007 sec.

(Interestingly, ascending order *seems* to work, did not test it thoroughly though.)

**Expected behavior**

Get the results in descending order, ie. `9, 8, 7, 6, 5`.

**Additional context**

Selecting the maximal value works:

        SELECT max(a) FROM mydb.mytable;
        ┌─max(a)─┐
        │      9 │
        └────────┘
        1 row in set. Elapsed: 0.007 sec.

After the rows are flushed to the backing MergeTree table, the results are good.

        OPTIMIZE TABLE mydb.mytable;
        SELECT a FROM mydb.mytable ORDER BY a DESC LIMIT 5;
        ┌─a─┐
        │ 9 │
        │ 8 │
        │ 7 │
        │ 6 │
        │ 5 │
        └───┘
        5 rows in set. Elapsed: 0.008 sec. 


{
    auto table_id = getStorageID();
    checkAlterIsPossible(params, local_context);
    auto metadata_snapshot = getInMemoryMetadataPtr();
    
    
    
    optimize({} , metadata_snapshot, {} , false , false , {}, local_context);
    StorageInMemoryMetadata new_metadata = *metadata_snapshot;
    params.apply(new_metadata, local_context);
    DatabaseCatalog::instance().getDatabase(table_id.database_name)->alterTable(local_context, table_id, new_metadata);
    setInMemoryMetadata(new_metadata);
}
void registerStorageBuffer(StorageFactory & factory)
{
    /** Buffer(db, table, num_buckets, min_time, max_time, min_rows, max_rows, min_bytes, max_bytes)
      *
      * db, table - in which table to put data from buffer.
      * num_buckets - level of parallelism.
      * min_time, max_time, min_rows, max_rows, min_bytes, max_bytes - conditions for flushing the buffer,
      * flush_time, flush_rows, flush_bytes - conditions for flushing.
      */
    factory.registerStorage("Buffer", [](const StorageFactory::Arguments & args)
    {
        ASTs & engine_args = args.engine_args;
        if (engine_args.size() < 9 || engine_args.size() > 12)
            throw Exception("Storage Buffer requires from 9 to 12 parameters: "
                " destination_database, destination_table, num_buckets, min_time, max_time, min_rows, max_rows, min_bytes, max_bytes[, flush_time, flush_rows, flush_bytes].",
                ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);