Fix GetPartialObject on FFS am: 4418030f am: 8eff2704

    uint64_t file_length = mfr.length;

    uint32_t given_length = std::min(static_cast<uint64_t>(MAX_MTP_FILE_SIZE),

            file_length + sizeof(mtp_data_header));

    uint64_t offset = 0;

    uint64_t offset = mfr.offset;

    struct usb_endpoint_descriptor mBulkIn_desc;

    int packet_size;

        packet_size = mBulkIn_desc.wMaxPacketSize;

    }

    int init_read_len = packet_size - sizeof(mtp_data_header);

    // If file_length is larger than a size_t, truncating would produce the wrong comparison.

    // Instead, promote the left side to 64 bits, then truncate the small result.

    int init_read_len = std::min(

            static_cast<uint64_t>(packet_size - sizeof(mtp_data_header)), file_length);

    char *data = mBuffer1.data();

    char *data2 = mBuffer2.data();

    if (TEMP_FAILURE_RETRY(pread(mfr.fd, reinterpret_cast<char*>(data) +

                    sizeof(mtp_data_header), init_read_len, offset))

            != init_read_len) return -1;

    if (writeHandle(mBulkIn, data, sizeof(mtp_data_header) + init_read_len) == -1) return -1;

    if (file_length == static_cast<unsigned>(init_read_len)) return 0;

    file_length -= init_read_len;

    offset += init_read_len;

    if (writeHandle(mBulkIn, data, packet_size) == -1) return -1;

    if (file_length == 0) return 0;

    // Break down the file into pieces that fit in buffers

    while(file_length > 0) {