If a QAbstractScrollArea widget in KCollapsibleGroupBox  has a huge sizeHint() [simulated here with QAbstractScrollArea::setSizeAdjustPolicy(QAbstractScrollArea::AdjustToContents) ] it will still try to fit it all expanding beyond screen size.

Reproducible: Always

Steps to Reproduce:
Formatted paste of the code attached as link

#include <QApplication>
#include <KCollapsibleGroupBox>
#include <QStandardItemModel>
#include <QTableView>
#include <QLabel>
#include <QVBoxLayout>
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QWidget mainWid;
    QStandardItemModel* model=new QStandardItemModel(&mainWid);
    model->insertColumns(0, 4);
    model->insertRows(0, 100);

    QTableView* view = new QTableView(&mainWid);
    view->setSizeAdjustPolicy(QTableView::AdjustToContents);
    view->setModel(model);

    KCollapsibleGroupBox* testGroup = new KCollapsibleGroupBox(&mainWid);
    testGroup->setTitle("Collapse");

    QLabel* testlabel = new QLabel(&mainWid);
    testlabel->setText("Test");

    QVBoxLayout* collapsibleLay = new QVBoxLayout(testGroup); 
    collapsibleLay->addWidget(view);

    QVBoxLayout* mainLay = new QVBoxLayout(&mainWid);
    mainLay->addWidget(testlabel);
    mainLay->addWidget(testGroup);
    mainWid.show();
    return a.exec();
}


Actual Results:  
view will expand beyond screen size

Expected Results:  
view will expand up to the maximum size allowed by the containing widget and use the scrollarea

Qt 5.5.1
Windows 7 32 bit