https://clickhouse-test-reports.s3.yandex.net/19475/02d28c1f9b9558ca5af267167a542819b9e1d061/fuzzer_debug/report.html#fail1
MutableColumns & left_columns, MutableColumns & right_columns, size_t & left_key_tail)
{
    const Block & right_block = *right_block_info.block;
    MergeJoinCursor right_cursor(right_block, right_merge_description);
    left_cursor.setCompareNullability(right_cursor);
    
    right_cursor.nextN(right_block_info.skip);
    right_block_info.skip = 0;
    while (!left_cursor.atEnd() && !right_cursor.atEnd())
    {
        Range range = left_cursor.getNextEqualRange(right_cursor);
        if (range.empty())
            break;
        right_block_info.setUsed(range.right_start, range.right_length);
        size_t max_rows = maxRangeRows(left_columns[0]->size(), max_joined_block_rows);
        if (!joinEquals<true>(left_block, right_block, right_columns_to_add, left_columns, right_columns, range, max_rows))
        {
            right_cursor.nextN(range.right_length);
            right_block_info.skip = right_cursor.position();
            return false;
        }
        right_cursor.nextN(range.right_length);
        
        if (right_cursor.atEnd())
        {
            left_key_tail = range.left_length;