title: Qt: Non ASCII characters in file names are replaced by '?'
body: <p>I have to work on a very reduced System. It's based on Ubuntu but not installed with the Ubuntu installer. So they are only really necessary packages and configuration. QtCreator is installed and works.</p>
  
  <p>When I try to create a file with a non ASCII character, the character is replaced by <code>?</code>. E.g.: <code>TestÄ.txt</code> will be named <code>Test?.txt</code>. But this only happens, when I use Qt functions. C++ standard library works.</p>
  
  <p>Example:</p>
  
  <pre><code>#include &lt;QDebug&gt;
  #include &lt;QFile&gt;
  #include &lt;fstream&gt;
  
  int main(int, char *[])
  {
      const char* fileName = "TestÄ.txt";
      qDebug() &lt;&lt; fileName;
  
      {
          QFile f(fileName);
          f.open(QIODevice::WriteOnly);
          f.write("QFile Äößń\n");
      }
  
      {
          std::ofstream f;
          f.open(fileName, std::fstream::app);
          f &lt;&lt; "std::ofstream Äößń\n";
      }
  
      return 0;
  }
  </code></pre>
  
  <p>There should be one file <code>TestÄ.txt</code> with two lines. But the first block creates the file <code>Test?.txt</code>. The second block works as expected. The content of the files is written correct.</p>