QPainter::drawPixmap crash can be reproduced using Scribble example and modifying the print method as shown below.

void ScribbleArea::print()
{
#ifndef QT_NO_PRINTER
    QPrinter printer(QPrinter::HighResolution);
 
    QPrintDialog printDialog(&printer, this);
//! [21] //! [22]
    if (printDialog.exec() == QDialog::Accepted) {
        QPainter painter(&printer);
        QRect rect = painter.viewport();

        QPixmap pm(15*logicalDpiX(), 15*logicalDpiY());
        pm.fill(Qt::blue);
        painter.drawPixmap(rect, pm);
    }
#endif // QT_NO_PRINTER
}

Demo application will crash and throws the following error message:
Application Specific Information:
error for object 0x10bfbf000: pointer being freed was not allocated.

Full crashlog attached to attachments.

Steps to reproduce:

• open scribble application
• draw a nice picture
• select File -> Print
• from the print dialog, select "Save as Pdf..." and save the file

Expected behaviour:

• Nice picture is being saved

Actual behaviour:

• Crash happens

Notes:
This issue is NOT valid on Qt5.01.