The visibility of placeHolderText of the QPlainTextEdit is not reevaluated in the setter

If empty text is set before setting the placeHolderText then the placeHolderText is not visible:

#include <QApplication>
#include <QPlainTextEdit>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QPlainTextEdit w;
    w.setPlainText("");
    w.setPlaceholderText("Qt is awesome!!!");
    w.show();
    return a.exec();
}

If instead if I reverse the order the placeHolderText is visible:

w.setPlaceholderText("Qt is awesome!!!");
w.setPlainText("");

Reviewing the source code I discovered that in setPlaceholderText the variable placeholderVisible is not reevaluated causing this unexpected behavior.

so a possible solution would be to invoke QPlainTextEditPrivate:: _q_textChanged in QPlainTextEdit::setPlaceholderText