encoding of GIOChannel

[Shixin Zeng <shixinzeng gmail com>]

The parent process use two pipes to communicate with the child, one
for read and the other one for write.

gboolean to_child(gpointer io)
{
  
  printf("%s\n", __FUNCTION__);
  GIOChannel *cl = (GIOChannel *)io;
    
  gchar *buff = g_new0(gchar, 1024);
  fgets(buff, 1024, stdin);
  GError *error = NULL;
  if(G_IO_STATUS_ERROR == g_io_channel_write_chars(cl, buff, 1024,
NULL, &error)){
    printf("error: %s", error->message);
  }
  g_free(buff);
  return TRUE; 
}

in main:
    GIOChannel *parent_in = g_io_channel_unix_new(pipe_child_stdout[0]); 
    GIOChannel *parent_out = g_io_channel_unix_new(pipe_child_stdin[1]);

    const char* charset;
    if(g_get_charset(&charset))
    if(G_IO_STATUS_ERROR == g_io_channel_set_encoding(parent_in, charset, NULL)
       || G_IO_STATUS_ERROR ==g_io_channel_set_encoding(parent_out,
charset, NULL)){/*IF I SET THE CHARSET TO NULL, IT WORKS FINE*/
      perror("Setting encoding error");
    }
    g_free(charset);
    
    g_io_add_watch(parent_in, G_IO_IN, from_child, main_loop);    
    g_idle_add(to_child, parent_out);


It compiles fine, but I got a runtime error, when I input something:
GLib: Cannot convert message: Conversion from character set 'UTF-8' to
'
' is not supported

GLib-ERROR **: file giochannel.c: line 2113
(g_io_channel_write_chars): should not be reached
aborting...

Program received signal SIGABRT, Aborted.

Any help?
My locales:
LANG=en_US.UTF-8
LC_CTYPE=zh_CN.UTF-8
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=

-- 
Best regards

Shixin Zeng