Why does it show me the message, Potential leak of memory when opening a QDialog

lincoln

Hi guys, I have the following code:

I make a connection to a QLabel to open a QDialog, to show the app license, through a lambda function, the problem I have is that it shows me the message of, Potential leak of memory, as you can see in the image, any suggestion why this happens.

connect(ui->lblLicencia,&QLabel::linkActivated,this,[&](){
    QDialog licenciDlg(this);
    QVBoxLayout *mainLayOut=new QVBoxLayout(&licenciDlg);
    QTextEdit *teLicencia=new QTextEdit(&licenciDlg);
    QFile fileName(":/licencia/licencia.txt");
    if(!fileName.open(QFile::ReadOnly | QFile::Text)){
      QMessageBox::warning(nullptr,qApp->applicationName(),"Error opening file..\n"+
                                                            fileName.errorString());
      return;
    }
    QString text=fileName.readAll();
    teLicencia->setPlainText(text);
    
    teLicencia->setReadOnly(true);
    mainLayOut->addWidget(teLicencia);
    licenciDlg.setLayout(mainLayOut);
    licenciDlg.setFixedSize(550,477);
    licenciDlg.exec();


  });

jsulm

@lincoln said in Why does it show me the message, Potential leak of memory when opening a QDialog:

mainLayOut

because you do not delete dynamically allocated memory in case you enter the if(...) part.
Warning explains exactly that.
Same applies to teLicencia...

lincoln

@jsulm
Ok great, if now the warning is no longer displayed, thanks for your answer.

add these two lines

delete mainLayOut;
delete teLicencia;

jsulm

@lincoln Actually you could simply move these two lines

QVBoxLayout *mainLayOut=new QVBoxLayout(&licenciDlg);
QTextEdit *teLicencia=new QTextEdit(&licenciDlg);

after

if(!fileName.open(QFile::ReadOnly | QFile::Text)){...}

then there is no need to delete anything. Create things when they are needed, not before.