title: UnicodeDecodeError using GLib.utf8_collate_key in Windows
body: <p>I'm using Python 3.3 / PyGObject 3.14 in Windows 7 and I have the following problem: Using either <code>gi.repository.GLib.utf8_collate_key</code> and <code>gi.repository.GLib.utf8_collate_key</code> with a non-ascii-only string always results in an <code>UnicodeDecodeError</code>.</p>
  
  <p>Test case:</p>
  
  <pre><code>&gt;from gi.repository import GLib
  &gt;asciiText = "a"
  &gt;unicodeText = "á"
  
  &gt;asciiText.decode()
  b'a'
  
  &gt;unicodeText.decode()
  b'\xc3\xa1'
  
  &gt;GLib.utf8_collate_key(asciiText, -1)
  'Aa'
  
  &gt;GLib.utf8_collate_key(unicodeText, -1)
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  UnicodeDecodeError: 'utf-8' codec can't decode byte 0xe1 in position 1: unexpect
  ed end of data
  </code></pre>
  
  <p>Expected result (from Linux)</p>
  
  <pre><code>&gt;GLib.utf8_collate_key(asciiText, -1)
  'a'
  
  &gt;GLib.utf8_collate_key(unicodeText, -1)
  'á'
  </code></pre>
  
  <p>The Windows system's locale is set to Portuguese (Brazil).</p>
  
  <p>Does anybody knows how to solve this? I'm considering rolling my own collating function if I can't get this to work.</p>