[critical] when find with chinese character

[lidaobing]

1. open iptux
2. Press "Cmd+F" to show the finder input box
3. input "中文" with input method, show critical with following:

$ ./src/main/iptux

(iptux:39974): Gtk-WARNING **: Locale not supported by C library.
	Using the fallback 'C' locale.

(iptux:39974): Pango-CRITICAL **: pango_layout_get_cursor_pos: assertion 'index >= 0 && index <= layout->length' failed

(iptux:39974): Pango-CRITICAL **: pango_layout_get_cursor_pos: assertion 'index >= 0 && index <= layout->length' failed

(iptux:39974): Pango-CRITICAL **: pango_layout_get_cursor_pos: assertion 'index >= 0 && index <= layout->length' failed

(iptux:39974): Pango-CRITICAL **: pango_layout_get_cursor_pos: assertion 'index >= 0 && index <= layout->length' failed