QUncompress can't read a file which was compressed with qCompress

mbertschi

Alright, all I want to do is to compress and uncompress a file with qCompress/qUncompress:

@QCoreApplication a(argc, argv);
QStringList args = QCoreApplication::arguments();

if(args.count() > 1){

if(args.at(1) == "-d"){//Decompress
QFile source(args.at(2));
if(source.open(QFile::ReadOnly)){
QByteArray compressedData = source.readAll();
QByteArray deCompressedData = qUncompress(compressedData);
source.close();
QFileInfo info(source);
QDir destinationDir(info.dir());
QFileInfo destinationInfo(destinationDir, info.baseName());

QFile destination(destinationInfo.absoluteFilePath());
destination.open(QFile::WriteOnly);
QTextStream destStream(&destination);
destStream << deCompressedData;
destStream.flush();
destination.close();

}
}
else{//Compress
QFile source(args.at(1));
if(source.open(QFile::ReadOnly)){
QByteArray compressedData = qCompress(source.readAll());
source.close();
QFileInfo info(source);
QDir destinationDir(info.dir());
QFileInfo destinationInfo(destinationDir, info.fileName() + ".gz");

QFile destination(destinationInfo.absoluteFilePath());
destination.open(QFile::WriteOnly);
QTextStream destStream(&destination);
destStream << compressedData;
destStream.flush();
destination.close();

}
}
}@

Oddly, qUncompress gives me "qUncompress: Z_DATA_ERROR: Input Data is corrupted", eventhough the original data was compressed with qCompress?