Quadratic QFrame becomes rectangular on iPhones with a home button

**Hi, I use some QFrames in my iPhone widgets app, and I notice that sometimes the geometry for them is distorted.

Steps to reproduce: make a new, empty vanilla Widget app. Then change your mainwindow.cpp to look like this:

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "qtimer.h"
#include "qframe.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    QTimer::singleShot(0,[this]
    {
        auto f1 = new QFrame(this);
        f1->setGeometry(100,100,100,100);
        f1->setFrameShape(QFrame::Box);
        f1->show();

        auto f2 = new QFrame(this);
        f2->setFrameShape(QFrame::Box);
        f2->setGeometry(110,110,100,100);
        f2->show();
    });
}

MainWindow::~MainWindow()
{
    delete ui;
}

Then run the app on an iPhone. See the screenshot: if you run it on an iPhone without a home button, you'll get the result on the left. But if you run it on an iPhone with a home button, you'll get the result on the right.

If I change the code so that  f2->setGeometry() occurs before f2->setFrameShape(), i.e. the same order as for the f1 QFrame, then all iPhones, even those with a home button look ok (both QFrames are quadratic).

If I comment out the QTimer so that the QFrames are constructed directly in MainWindow's ctor (and not in the lambda), then all iPhones, even those with a home button look ok (both QFrames are quadratic).

If this is a feature: I cannot find any documentation about QFrames having to be initialized in the order: first set the geometry, then the shape. Please fix the documentation.