(button_set_text): update value of WButton::hotpos.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>

lib/widget/button.c

@@ -2,7 +2,7 @@
    Widgets for the Midnight Commander
 
    Copyright (C) 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003,
-   2004, 2005, 2006, 2007, 2009, 2010, 2011
+   2004, 2005, 2006, 2007, 2009, 2010, 2011, 2013
    The Free Software Foundation, Inc.
 
    Authors:
@@ -11,7 +11,7 @@
    Jakub Jelinek, 1995
    Andrej Borsenkow, 1996
    Norbert Warmuth, 1997
-   Andrew Borodin <aborodin@vmail.ru>, 2009, 2010
+   Andrew Borodin <aborodin@vmail.ru>, 2009, 2010, 2013
 
    This file is part of the Midnight Commander.
 
@@ -240,6 +240,7 @@ button_set_text (WButton * b, const char *text)
 
     release_hotkey (b->text);
     b->text = parse_hotkey (text);
+    b->hotpos = (b->text.hotkey != NULL) ? str_term_width1 (b->text.start) : -1;
     w->cols = button_get_len (b);
     widget_redraw (w);
 }