QBuffer::readLine()

[vfernandez]

#include <QtCore>
 
int main(int argc, char *argv[])
{
  QCoreApplication app(argc, argv);
  QBuffer buf;
  buf.open(QIODevice::ReadWrite);
  buf.write("Hello!\n");
  qDebug() << buf.data();                  // prints Hello!\n
  qDebug() << buf.canReadLine();           // returns false!
  qDebug() << buf.readLine();              // returns an empty string!
}

#include <QtCore>

int main(int argc, char *argv[])
{
  QCoreApplication app(argc, argv);
  QBuffer buf;
  buf.open(QIODevice::ReadWrite);
  buf.write("Hello!\n");
  qDebug() << buf.data();                  // prints Hello!\n
  qDebug() << buf.canReadLine();           // returns false!
  qDebug() << buf.readLine();              // returns an empty string!
}

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I'm using QBuffer for a unit test and I've found this behaviour. I'm using 4.6.2. The Qt docs state you can use readLine() but in fact it returns an empty string. Is this correct or a Qt bug?

[wysota]

This is correct. You didn't rewind the buffer. If you seek to the beginning of the buffer, you will be able to read from it.

[vfernandez]

Oops! Dzękuje.