title: Chinese characters not shown in embedded system (yocto, Qt 5.5.1) - why Qt doesn't use system fonts?
body: <p>While the following code works on both, desktop Linux and Windows, chinese characters are shown like white space on an embedded linux (yocto jethrow, Qt 5.5.1, Qt on X11). It seems that Qt uses its own fonts and not the system fonts on this system. Note: after "Hello World" there should be the chinese "nihao".</p>
  
  <p>C++ content of main():</p>
  
  <pre><code>QApplication a( argc, argv );
  QString s =  QString::fromUtf8("Hello world \u611b!");
  QPushButton hello;
  // eventually set font here, see below
  hello.setText(s);
  hello.resize( 200, 30 );
  hello.show();
  return a.exec();
  </code></pre>
  
  <p>On another embedded system which used Qt 4, it was sufficient only to install a proper font. The font is also correctly installed here and recognised by fc-list. </p>
  
  <p>If I modify the code above and set the font directly, it works as expected:</p>
  
  <pre><code>// insert font here:
  int id = QFontDatabase::addApplicationFont("/usr/share/fonts/wqy/wqy-microhei.ttc");
  QString family = QFontDatabase::applicationFontFamilies(id).at(0);
  QFont font(family);
  hello.setFont(font);
  // end modification
  hello.setText(s);
  </code></pre>
  
  <p>If I make a simple qml script, I also have to set the font. 
  If I use a web engine browser widget however, it can display chinese characters.</p>
  
  <p>The fonts which are shown by the command "fc-list" (liberation, wqy-microhei) and with the qt function " Qt.fontFamilies()" (bitstream, luxi, dejavu, curier, cursor, utopia) are different. </p>
  
  <p>Is it possible to change the qt configuration without recompiling qt or the application in order that wqy-microhei is used for the chinese characters?</p>