Extremely wide QFileDialog windows, regression in 5.13, 5.14, or 5.15

After upgrading Qt from 5.12 to 5.15, one of my QFileDialog windows has become extremely wide, see attached image. The reason seems to be this line:

https://code.qt.io/cgit/qt/qtbase.git/tree/src/widgets/dialogs/qfiledialog.cpp#n3083 

I.e. this line:

qFileDialogUi->fileTypeCombo->setSizeAdjustPolicy(QComboBox::AdjustToContentsOnFirstShow);

should IMHO look like this:

qFileDialogUi->fileTypeCombo->setSizeAdjustPolicy(QComboBox::AdjustToMinimumContentsLengthWithIcon);

Workaround if using Qt 5.15:

  static inline void fixqfiledialog(QWidget *widget){
    if (widget != NULL){
      QComboBox *box = dynamic_cast<QComboBox*>(widget);
      if (box != NULL)
        box->setSizeAdjustPolicy(QComboBox::AdjustToMinimumContentsLengthWithIcon);
      
      for(auto *c : widget->children())
        fixqfiledialog(dynamic_cast<QWidget*>(c));
    }
  }