Libarchive creates empty file called T while archiveing

[Bharathi Nandhan]

Am using Qt for my development. Below is the code which i used for creating tar.gz files. 

Few times while creating tar.gz it creates an empty file T with 0 bytes of memory usage. What am i doing wrong here

    /**
     * @brief Create a tar bundle
     * @param QMap<SaveFileName, SaveFilePath> m_SaveFile - url of file
     * @param QMap<FileName , FilePath> m_FilesToTar - Files to be tar bundled
     * @return 0 on failure 1 on success
     */

bool SSL_ED::CreateTarBundle(QMap<QString, QString> m_SaveFile, QMap<QString, QString> m_FilesToTar, unsigned int i_FileType)

{

    if( m_SaveFile.size() != 1 ) {

        qDebug() << "Invalid tar bundle save location or filename";

        return false;

    }

    if ( !QDir::setCurrent(m_SaveFile.value(m_SaveFile.firstKey())) ) {

        qDebug() << "Bundle creation: Unable to change dir";

        return false;

    }

    struct archive *a;

    struct archive_entry *entry;

    struct stat st;

    a = archive_write_new();

    archive_write_add_filter_gzip(a);

    archive_write_set_format_pax_restricted(a);

    archive_write_open_filename(a, m_SaveFile.firstKey().toUtf8().constData());

    QMapIterator<QString, QString> mItr(m_FilesToTar);

    while(mItr.hasNext())

    {

        mItr.next();

        if( !QDir::setCurrent(mItr.value()) ) {

            qDebug() << "Bundle creation: Unable to change dir to read file";

            return false;

        }

        const char *filename = mItr.key().toUtf8().constData();

        stat(filename, &st);

        entry = archive_entry_new();

        archive_entry_set_pathname(entry, filename);

        archive_entry_set_size(entry, st.st_size);

        archive_entry_set_filetype(entry, AE_IFREG);

        archive_entry_set_perm(entry, 0644);

        archive_write_header(a, entry);

        QFile file(mItr.value()+mItr.key());

        qDebug() << "FileName:"<<mItr.value()+mItr.key();

        if (!file.open(QIODevice::ReadOnly))

        {

            qDebug() << "Unable to read file for creating tar:"<<file.fileName();

            return false;

        }

        char c_ReadData[512000];

        qint64 i_ReadData = file.read(c_ReadData,512000);

        while( i_ReadData > 0 )

        {

            int i = archive_write_data(a, c_ReadData, static_cast<size_t>(i_ReadData));

            if ( i == ARCHIVE_RETRY || i == ARCHIVE_WARN ||

                 i == ARCHIVE_FAILED || i == ARCHIVE_FATAL )

            {

                qDebug() <<"Fatal error while creating tar file: "<<i;

                return false;

            }

            i_ReadData = file.read(c_ReadData,512000);

        }

        file.close();

        file.flush();

        archive_entry_free(entry);

    }

    if ( ARCHIVE_OK != archive_write_close(a) ){

        return false;

    }

    if ( ARCHIVE_OK != archive_write_free(a) ){

        return false;

    }

    return true;

}