title: Adding detailed text in QMessageBox makes close (X) button disabled
body: <p>I noticed an interesting thing - if I add a detailed text to QMessageBox (which adds "Show Details..." button) then executing it will show the system frame's close (X) button disabled and hence marking this window as non-closable (right click on frame -> Close disabled).</p>
  
  <p>Here is some sample code:</p>
  
  <pre><code>QMessageBox box(QMessageBox::Critical, title, text, QMessageBox::Ok);
  box.setDetailedText(detailedText); // comment this line to get close button enabled
  box.exec();
  </code></pre>
  
  <p>I didn't even find a way to manually do this in Qt. Any ideas?</p>
  
  <p>Thanks</p>