QLineEdit and QTextEdit do no append pastes to the undo stack

When using a QLineEdit or QTextEdit, doing a paste operation does not append the change to the undo stack. This is not standard behavior as each pastes are appended to an undo stack separately on Windows, Mac or GTK applications.

How to reproduce:
1) Compile and run simple application

#include <QApplication>
#include <QLineEdit>

int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QLineEdit mainWin(NULL);
mainWin.show();
return app.exec();
}

2) Enter 1,2,3 into line edit
3) Select '123' and press 'copy' from popup menu (or press Ctrl+C).
3) Press Ctrl+V to paste from clipboard (don't use Paste from popup menu!)
4) Press Ctrl+V to paste from clipboard (don't use Paste from popup menu!). After this step line edit should contain '123123123' text
5) Press Ctrl+Z . Line edit should contain '123123', but contain '123'