[Fix] xmp-openmpt: Fix xmplay_streambuf::underflow(). When returning …

…eof, we also need to set the get area to empty according to the standard.

git-svn-id: https://source.openmpt.org/svn/openmpt/trunk/OpenMPT@20365 56274372-70c3-4bfc-bfc3-4c3a0b034d27

libopenmpt/xmp-openmpt/xmp-openmpt.cpp

@@ -537,10 +537,10 @@ std::streambuf::int_type xmplay_streambuf::underflow() {
  start += put_back_count;
  }
  std::size_t n = xmpffile->Read( file, start, buffer.size() - ( start - base ) );
+ setg( base, start, start + n );
  if ( n == 0 ) {
  return traits_type::eof();
  }
- setg( base, start, start + n );
  return traits_type::to_int_type( *gptr() );
 }